ANATOMYA. Embryology

1. Pharyngeal Arches

M08Q2 Clinical examination of a patient includes the testing for sensation on the skin of the face as well as closing the eyelids and clenching the teeth. Give an account of the innvervation and development from the pharyngeal arches for the following

a. skin of the face (30%)b. muscles of facial expressions (30%)c. muscles of mastication (40%)

M04Q5c Describe the embryological basis for the abnormal location of the parathyroid glands. (20%)M02Q3a Biopsy of a lump on the dorsum of the tongue in a young boy reveals

thyroid tissue. Give an account of the development of the thyroid gland explaining the above finding.

M00Q8 Describe the formation (origin) and development of the third and fourth pharyngeal pouches.

A98Q2b Which pharyngeal pouches give rises to endocrine glands? How do these pouches develop?

J96Q1b Write short notes on the development of the thyroid gland.M96Q1a Describe the development of the third and fourth pharyngeal pouches.M94Q1a Describe the development of the thyroid gland with a note on the

associated congenital abnormalities.J92Q3a Describe the development of the pharyngeal pouches.M92Q5a Describe the derivatives of the first three pharyngeal arches (excluding

blood vessels)M91 Q4b Write short notes on the derivatives of the pharyngeal arches.M90Q5b Briefly describe the development of the pharyngeal (branchial) pouches.

2. Palate

M01Q4 A child with speech difficulty is found to have a cleft palate. Describe the development of the palate and review the types of abnormalities that may be associated with it.

J98Q1a Describe the formation of the palate and indicate some common abnormalities.J96Q1a Describe the formation of the palate.M94Q1b Describe the developmental basis for the cleft lip and palate.M90Q5a Correlate the development of the palate with some off its common

abnormalities.

3.Tongue

M04Q6 (a) Outline the development of the tounge, and correlate this with its external features and innervation. (70%) M01Q4 Give an account of the development of the tongue. Correlate, where

possible, its external morphology and nerve supply.A99Q 1 Write short notes on the development of the tongue. Give the

embryological basis for its innervation.J98Q1b How does the tongue develop from the various primordia? What is the

embryological basis for its innervation?A95Q1a Describe the development of the tongue.

1

ANATOMY4. Face

A98Q1a Correlate the development of the face with its gross anatomy.J97Q1b Describe briefly the development of the face, and correlate with

congenital defects.M96Q1b Give an account of the development of the face, including a note on the

musculature and innervation.A95Q1b Describe the development of the face with a note on the associated

abnormalities.J94Q1b Describe the development of the face, making correlation with its sensory

and motor innervation.M93Q1b Describe the development of the face.

5. Heart

J97Q1a Give a brief account of the development of the right and left atria.J91Q3a Describe the development of the right atrium.

6. Aortic Arches

J93Q1b/ Describe the development of the aortic arches.

7. GIT

J85Q5b Describe the development of the pancreas.

8. Nervous Tissues

M91Q4b Write short notes on the development of the neural tube.

9. Miscellaneous

A97Q 1 a Give an account of the development of the endocrine glands in the neck.

B Histology

1. Cells / Tissues

J92Q5b Describe the histological features of the pseudostraitified columnar ciliated epithelium.

2. Muscles

M08A4 b) Describe the histological features of cardiac muscle. How does it differ histologically from skeletal and smooth muscle? (40%)

A97Q2b Describe the histological features of the cardiac muscle and compare them with the other muscle tissues (skeletal and smooth).

M96Q2a Give an account of the light and electron microscope features of cardiac muscles.

J91 Q2b Write short notes on the histological features of cardiac muscles.M91Q5a Describe the histological features of cardiac muscle.

3. Bone

A95Q2b Describe the histological features of the intramembranous ossification.J94Q2a Describe the light microscopic features of compact bone.

2

ANATOMY

4. Respiratory Tract

A99Q2 Describe the histological features of trachea.J94Q2b Write short notes on the histological features of the trachea.

5. GIT

M04Q6b Describe briefly the light microscopic features of the mucosa of the tounge. (30%)A97Q12a Describe the histological features of mixed salivary glands.J96Q2a Describe the histological features of the tongue.M91Q5b Describe the histological features of the duodenum.M90Q2a Give an account of the histological features of the duodenum.

6. Endocrine

M02Q3b Biopsy of a lump on the dorsum of the tongue in a young boy reveals thyroid tissue. Describe the light microscope features of the thyroid glands.

M00Q7 Describe the histological structures of the thyroid and parathyroid glands.J98Q2 Describe the histological features of the thyroid gland.J97Q2a Give the histology of the thyroid and the parathyroid gland.A95Q2a Give an account of the histology of the thyroid gland.J93Q2a Describe the light microscopic features of the thyroid gland.M93Q2b Write short notes on the histology of the pituitary gland.M92Q4a Write short notes on the histological features of the parathyroid glands.M90Q4a Write short notes on the thymus gland.

7. Thymus/ Lymph Nodes/ Tonsils

A98Q2a Correlate the histological features of the lymph node with its functions.J97Q2b Describe the histology of the lymph node.M94Q2a Describe the histological features of the thymus.M93Q2a Describe the microscopic structure of the palatine tonsil.M92Q4b Write short notes on the functional histology of the palatine tonsil.

8. Miscellaneous

J96Q2b Describe the histological features of thin skin.J92Q5a Give an account of the ultrastructural features of a typical neuron (with

special emphasis on the chemical synapse).

C. Neuroanatomy

M01Q1 (b)What are the effects of lesions affecting the 3rd, 4th and 6th cranial nerves, respectively?

A99Q3 Give an account of the functional localisation of the cerebral cortex.

J98Q3a i) List the structures supplied by the branches of the facial nerve and give the

name of the nucleus/ganglion supplying them.ii) What are the differences between an upper and a lower motor neuron

lesion

3

ANATOMYaffecting the facial nerve? Give the neuroanatomical basis for thedifferences.

J98Q3b Describe the possible course of the axon of a preganglionic sympathetic ganglion neurons.List the structures supplied by the superior cervical sympathetic ganglion neurons.

A98Q3 a) Name the nerves supplying the various structures of the tongue and thelocation of their cell bodies. Differentiate an upper and a lower motorlesion affecting the nerve supplying the tongue.

b) Describe the possible course of the axon of a preganlionic sympatheticneuron. List the structures a postganglionic sympathetic neuron mayinnervate.

J97Q3a A patient complained of dryness of the mouth. Clinical examination revealed that his right lingual nerve had been severed just distal to the lower third molar tooth during an intraoral operative procedure.i) Outline the neuroanatomical pathway/s from the brain to the salivary

glandssupplied by the lingual nerve.

ii)What sensory deficits would the patient experience after severance of the

lingual nerve? Trace the pathway/s for one of the sensations transmitted by

the nerve.

J97Q3b With regard to the facial motor neurons:i) List the afferents to the neurons.ii) Give a brief account of the pathways for the corneal reflex effected

by the neurons.iii) What are the differences between an upper and lower facial

motorneuron lesions? Give the neuroanatomical basis for the differences.

A97Q3 a) Give an account of the conscious and unconscious proprioceptivepathways from different parts of the body.

b) With regard to the glossopharyngeal nerve:i) List its functional components and indicate the locations of the

cell bodies and structure/s supplied by them.ii) Give an account of the central connections of a motor

component of the nerve.iii) What are the consequences of damage to the sensory

components of the nerve?

J96Q3 a) i) State the functional components of the trigeminal nerve.ii) List the structures supplied by the various branches of the nerve and the nucleus or ganglion in which the cell bodies of these

nerves are located.iii) Trace the central pathways of one of the sensory components of the nerve.

b) Give an account of the various afferents to the spinal motor neuronswhose axons supply the skeletal muscles.

4

ANATOMYM96Q3a i) State the functional components of the lingual nerve at the point where

the nerve lies beneath and behind the lower third molar.ii) List the structures supplied by the nerve and the nucleus/ ganglion

which the cell bodies of the nerves supplying them are located.iii) Trace the central pathways of one of the sensory components of the

nerve.

M96Q3b Give an account of the visual pathway and the pathway/s for pupil constriction.

M95Q3a Give an account of the pathways mediating 1)jaw jerk reflex, 2) corneal reflex.

A95Q3b Tabulate the functional components of the seventh cranial nerve (facial nerve),

listing the structures supplied by the branches of the nerve, and the name of

the nucleus/ganglion supplying them. What are the differences between an

upper and a lower motor neuron lesion affecting the nerve?

J94Q3a Describe the possible pathways taken by the axons of neurons present in the

intermediolateral nucleus in the spinal cord.

J94Q3b Tabulate the functional components of the facial nerve, listing the structures

supplied by the nerve and name the nucleus/ ganglion supplying them. Describe briefly the central connections of one of the sensory components of the nerve

M94Q3a Tabulate the functional components of the glossopharyngeal nerve, listing the structures supplied by the nerve and the name of the nucleus/ ganglion supplying the structures.Give an account of the central connections of one of the functional components of the nerve.

M94Q3b Give a brief account of the pathways mediating the pupillary (including consensual light) reflex.

J93Q3a Give a brief description of the tracts present in the white matter seen in the transverse section of the spinal cord at the upper cervical level and indicate their functional importance.

J93Q3b List functional components of the glossopharyngeal nerve, giving names of the respective nuclei/ ganglion and the structures supplied by them. Write a brief account of the central connections of one of the functional components.

M93Q3a List the structures supplied by the sensory fibres of the trigeminal nerve and describe the central pathways whereby pain and temperature modalities transmitted by the nerve reach the cortex.

5

ANATOMYM93Q3b Describe the neural pathways conducting gustatory impulses from the

peripheral to the central nervous system.

J92Q4 Tabulate the functional components of the lingual nerve diesel to its junction with its chorda tympani, giving the locations of their cell bodies and names of structures supplied by them. Describe the central connections of one of the functional components.

J92Q4b Describe the differences between an upper and a lower motor neuron lesion affecting the facial nerve.

M92Q1a Describe the course and distribution of the axons of neurons in theintermediolateral nucleus.

M92Q1b List the functional components of the glossopharyngeal nerve, indicating theirtarget organs and locations of their cell bodies. Describe the central connections of one of its visceral components.

J91Q1 a Describe briefly the possible routes that the axon of a preganglionicsympathetic neuron might take. Which spinal segment levels do mostpreganglionic to the superior cervical ganglion take their origin?

J91Q1b List the functional components of the vagus nerve. Describe briefly thecentral connections up to the level of consciousness of ONE of the sensorycomponents.

M91Q1a Give an account of the supraspinal pathways that influence the motor neurons in the spinal cord.

M91Q1b Give a brief account of the general visceral fibres travelling with the cranial nerves with regard to their target organs, cell bodies and central connections.

M90Q1a Describe the central connections of the auditory pathway.

M90Q1b Describe the pathways involved in the upper motor neuron lesion control of facial musculature. Differentiate between upper and lower motor neuron lesion affecting the facial motor nucleus.

D. Gross Anatomy

D1. Thorax

1. Heart

M08Q4 a) Describe the arterial supply to the heart (30%)b) Write short notes on the conducting system of the heart (30%)

M91Q1 Describe the surfaces of the heart, including the blood vessels on the surfaces.

2. Lung

M91Q4 Describe briefly how the antero-posterior, transverse and vertical dimensions of the thorax increases during inspiration.

J91 Q4a Describe the gross anatomy of the left lung.

6

ANATOMYM90Q6b Give an account of the gross anatomy of the pleura.

3. Thoracic Duct

J86Q6b Describe briefly on the course and relations of the thoracic duct.M82Q5b Write a short account of the gross anatomy of the thoracic duct.J81 Q3b Write short notes on the formation, course and area of drainage of the

thoracic duct.

4. Diaphragm

M91Q2 Describe the gross anatomy of the diaphragm.

5. Oesophagus

M87Q5b Give an account of the gross anatomy of the oesophagus.M86Q4b Describe briefly the gross anatomy of the thoracic part of the oesophagus.

6. Miscellaneous

M03Q6 Give a brief description of:(a) the coronary circulation(b) the mechanism of breathing

J91 Q6a Describe the relations of the trachea in the neck.M91 Q6a Define the boundaries of the superior mediastinum and describe the

relations of the structures within.

D2. Abdomen

A92Q3 Write short notes on the gross anatomy of the spleen.J91 Q4b Describe the arterial blood supply and venous drainage of the stomach.M91Q6b Define the formation and relations of the hepatic portal vein and list the

portal – systemic anastomosis.M90Q3a Write short notes on the blood supply of the stomach.

D3. Head and Neck

1. Thyroid Gland

M07Q1d Briefly outline the light microscopic features of the thyroid gland. (25%)M05Q3 Give a description of the thyroid gland and include its relations and

histology (100%) M04Q5 A middle-aged lady, undergoing surgery for removal of thyroid gland because of cancer, is found to have only 2 parotid glands in their normal location.

(a) What are the main relations of the thyroid gland? (60%)(b) Outline the blood supply of the gland and the effects of injuring the

nerves that are closely related to these vessels. (20%)

M01Q2 Give an account of the extent and main relations of the thyroid gland. Outline the light microscopic features of this gland.J98Q2b Describe the relations and blood supply of the thyroid gland.M90Q4a Describe the gross anatomy of the thyroid gland.

2. Salivary Gland

7

ANATOMY

M07Q3 Describe the parotid gland with reference to its: (a) Contents and main relations (40%) (b) Secretomotor innervations, and (40%) (c) Light microscopic features. (20%)M06Q4 A 30 year old female patient had surgery done on the left parotid gland of

removal of a tumour. Following the surgery, the left eye could not close, there was constant tearing and dribbling from the mouth.(a) Describe the relations and innervations of the parotid gland. (60%)(b) What are its histological features? (40%)

M04Q4 (a) Describe the location and relations of the parotid gland. (60%) (b) Give a brief account of its secretomotor innervation. ( 20%) (c) Outline the main light microscopic features of the gland. ( 20%)

M03Q2a Give an account of the location, relations and secretomotor innervation of the submandibular gland.

M03Q2b Outline the main light microscopic features of the gland.M02Q4 A middle aged lady requires surgical removal of her right parotid gland for a

cancerous growth. a. Give an account of the major relations of the parotid gland. b. Briefly trace the extracranial course of the secretomotor fibres to the

gland.M01Q5 A patient requires total removal of the submandibular gland for infection.

(a) Briefly describe the histology of the submandibular gland.(b) What are the relations of the submandibular gland?

M00Q4 Give an account of the parotid gland under:(a) extent and relations(b) secretomotor innervation

M98Q1b Give an account of the location, extent, relations and innervation of the parotid gland.

J94Q5b Describe the relations and innervation of the submandibular gland.J92Q1b Give the extent, relations and innervation of the parotid gland.M92Q2a Describe the gross anatomy of the submandibular gland.M91Q2b Describe the relations and innervation of the parotid gland.

3. Lacrimal Apparatus

M89Q3b Describe the anatomy of the secretion and drainage of tears (including secretomotor innervation)

J82Q2c Give an account of the gross anatomy of the lacrimal gland and its drainage system.

4.Tongue

M08Q1 A patient complained of dryness of the mouth and loss of sensation following tooth extraction for which an injection of local anesthetic had been given.a. Write short notes on the sensory and motor supply to the tongue (10%)b. Describe the extrinsic muscles of the tongue, including their actions.c. Give an explanation for the dryness in the patient’s mouth, and write a short description of the histology of the glands involved. (40%)

M05Q4 Briefly describe the tongue with reference to its:a. innervation- general sensory, special sensory and motor supply (60%)

8

ANATOMYb. mucuous membrane (20%)c. What are the extrinsic muscle of the tongue? (20%)

M03Q3a Describe the external morphology of the tongue and correlate this with development and sensory innervation.

M03Q3b What are the main light microscopic features of the mucosa of the tongue?M92Q3a Describe the innervation of the tongue.

5. Palate

A99Q8 Describe the structure of the palate (hard and soft) including its innervation

and blood supply.M91 Q3b Write short notes on the gross anatomy of the soft palate.

6. Nasal Cavity

M88Q3b What are the surface features of the lateral wall of the nasal cavity (excluding osteology)?

J86Q3a Write briefly on the gross features of the lateral wall of the nasal cavity (excluding blood and nerve supply).

J82Q2b Describe briefly the lateral wall of the nasal cavity.

7. Maxillary Sinus

M08Q3 A patient has infection of an upper molar which has involved the maxillary sinus.

a. Describe the relations and drainage of the maxillary sinus (40%)b. What are the nerves that supply this sinus? (40%)c. Describe the lining epithelium of this sinus. (20%)

J96Q4b Describe the gross anatomy of the maxillary sinus.

8. Pharynx

M06Q2 Degluition involves the coordinated action of a number muscles of the oral cavity, pharynx and larynx.(a) Review the oral, pharyngeal and oesophageal phases of deglutition.

(60%)(b) State the innervations of muscles involved during these phases. (20%)(c) List some causes of dysphagia. (20%)

M04Q1 / A patient with bleeding from the nose is diagnosed with cancer of the nasopharynx. Spread of the tumour to nearby structures is suspected as he has difficulties with movements of the right eye.

(a) Describe the main internal features and relations of the nasopharynx. ( 50%)

(b) List the normal movements of the eye, and name the muscle that produce the movements, as well as stating the innervation of these muscles. ( 50%)

M01Q3 Describe the internal features and relations of the nasopharynx.J98Q5aM96Q5a Give an account of the gross anatomy of the nasopharynx.A95Q5a Describe the gross anatomy of the muscles of the pharynx and their

innervation.

9

ANATOMYJ94Q5a Give an account of the internal features and relations of the nasopharynx.M94Q4b Describe the internal features and relations of the nasopharynx.

9. Larynx

MOOQ5 Write on the following aspects of the larynx(a) internal features and sensory innervation(b) movements of vocal folds and muscles that help to produce them.

A97Q5b Give an account of the movement of the vocal folds.M96Q5b Describe the intrinsic muscles of the larynx including their actions and

innervations.M93Q5b Describe the movements of vocal folds and indicate the muscles

responsible for such movements.

10. TMJ, Mandibular Movements and Muscles

M06Q3 A patient has difficultly in chewing following surgical procedures on the lower third molar, due to trauma to the TMJ.(a) What nerve is likely to have been injured during surgery, and describe

the functional loss that would have resulted? (40%)(b) Explain the various types of movements at the TMG based on the

attachments if the muscles that aid mastication. (60%)

M05Q1b Name the muscles that act directly on the temporomandibular joint, and give a summary of their actions. (50%)

M04Q2 a. Give a brief account of the tomporomandibular joint. ( 40%)b. List the movements at thes joint and indicate the muscles responsible

( 40%)c. Correlate the ultrastructure ( electron microscopic features) of skeletal muscle with the mechanism of muscular contraction. ( 20%)

M02Q2 A patient presented with a dislocated temporomandibular joint (TMJ) at the Emergency Department. a. Describe the gross anatomical features of the joint. b. Describe the normal movements of the joint indicating the various

muscles that produce them.M01Q3 A patient presents with dislocation of the temporomandibular joint.

(a) Describe the gross anatomical structure of the joint.(b)List the normal movements at the joint indicating the muscles that produce them.

A99Q5 (a) Describe the structure of the temporomandibular joint.(b) What are the movements that take place at the joint?(c) What muscles are responsible for the movements?

J98Q5b What are the major movements of the mandible? Briefly describe the attachments of the muscles which produce the various movement.

A97Q4a Give an account of the temporomandibular joint.J96Q4a Describe the TMJ, including its movements and the muscles producing the

movements.J94Q4b Describe the attachments, actions and relations of the medial pterygoid

muscle.

10

ANATOMYM94Q5b What are the movements that take place at the TMJ? Name the muscles

responsible for these movements and the attachments of these muscles.J93Q5a Describe the gross structure of the TMJ and the movements that take

place at the joint.M93Q4a Give an account of the attachments, relations, innervations and actions of

the lateral pterygoid muscles.M92Q2a Give an account of the TMJ.J91 Q3a Describe the TMJ (excluding relations). Indicate the various movements

and the muscles responsible.

11. Ear

M00Q2 Describe the walls and relations of the middle ear.A99Q7 Give an account of the walls and relations of the middle ear.A98Q5b What structures are closely related to the walls of the middle ear? Give a

brief account of the distribution of the nerve(s) associated with the walls.J93Q5b What are the relations of the middle ear?

12. Cavernous Sinus

M05Q6 The cavernous sinus is often at risk from spread of infection from the face or during the spheniodal procedures on the pituitary gland.(a) Describe the formation, connections and relations of the cavernous

sinus. (80%)(b) What other intracranial or extracranial structures may drain into dural

venous sinuses? (20%)M02Q6 A patient is diagnosed with carvenous sinus thrombosis following infection of

the face. Give an account of the locations, relations and communications of the cavernous sinus.

M01Q6 An infection from the face is suspected to have spread to a cavernous sinus. Give an account of the carvernous sinus, including its relations and drainage/ communications.A99Q6 Give an account of the

(a) location,(b) tributaries and drainage, and(c) relations of the cavernous sinus.

A98Q4a Give an account of the relations and connections of the cavernous sinus. Add a note to the formation of the sinus.

J97Q5b Describe the gross anatomy of the cavernous sinus, including its relations and

communications.M96Q4a Give an account of the gross anatomy of the cavernous sinus.A95Q4a Give an account of the relations of the cavernous sinus. Along which

venous pathways can infections spread to the sinus?

13. Blood Vessels

M07Q1 A middle aged lady was found to have a large thyroid tumour occupying the thoracic inlet (superior thoracic aperture). She also had evidence of compression at the inlet. The tumour was removed surgically. (a) List the structures, including major vessels and nerves, that pass between the neck and the thorax. Indicate their position, where possible (25%) (b) What are the possible consequences of the compression? (25%) (c) Name the vessels that need to be ligated (tied) before the thyroid tumour

11

ANATOMY can be safely removed. Some nerves may be closed to these vessels. What might be the result of the injury to these nerves?M06Q5 Severe bleeding in the head and neck sometimes requires ligation of the

external carotid artery.(a) Outline the origin, course, branches and distribution of the external

carotid artery. (60%)(b) What are its relations at its origins? (20%)(c) What are the possible sources of collateral circulation if the artery is

ligated? (20%)M05Q5 Give an account of external carotid artery in terms of its branches and the

structures or regions that they supply. (100%)M04Q3 Describe the course, relations, branches and distribution of the right subclavian artery .M03Q5 Briefly describe the origin, course, branches and distribution of the external

carotid artery. What are some routes for collateral circulation in the event of obstruction to this

artery?M02Q5 (a) Describe the course and relations of the right subclavian artery. (b) Outline the areas of supply of this artery and list its major branches.M01Q2 A carotid angiogram is done by injecting contrast into the common carotid artery. Describe the course, branches and distribution of the external carotid artery.J98Q4b Give an account of the relations of the internal jugular vein.J97Q5a Describe the internal features of the nasal cavity. What are the main

sources of innervation and arterial supply to the lining of the cavity?J96Q5a Review the course and branches of the subclavian artery to the head and neck.J94Q4a Give an account of the origin, course and relations of the left common

carotid artery.M94Q4a Describe the origin, course and distribution of the external carotid artery.J93Q4b Give an account of the relations of the cervical part of the common carotid

artery.J92Q2a Describe the origin, course and distribution of the maxillary artery.

14. Nerves

M07Q4 A patient has a painful lower 3rd molar which requires extraction. (a) What are the 3 nerves that may require to be anesthetized? (20%) (b) What are the functional components of these nerves, and what is the effect of anesthetizing them? (50%) (c) Describe the pain pathway from this tooth to the cerebral cortex. (30%)M05Q1a Write an account of the mandibular nerve in terms of its motor and sensory

nerve supply. (50%)M05Q2a Describe the face in terms of its cutaneous innervationM03Q1 (a) Outline the course and distribution of the maxillary nerve. (b) Give a brief description of the central connections for pain in this nerve.M02Q1 During an operation to remove the lower right third molar (wisdom tooth),

the lingual nerve of the patient was accidentally damaged. a. Describe the extracranial course and relations of the nerve. b. Explain the functional loss following the damage to the nerve.

M01Q1 Describe the course, branches and distribution of the mandibular division of the trigeminal nerve.M01Q7 A patient presents with the weakness of facial expression on one side.

12

ANATOMY(a) Describe the pathway for innervation of the muscles of facial

expression.(b) What are the effects of lesions affecting the pathway at the upper and

lower motor neuron levels? M00Q6 (a) Describe the sensory innervation of the lower third molar and the

gingivae on the buccal and lingual aspects of the tooth.(b) Describe the central pathway by which pain from the tooth is

transmitted to the primary somatosensory cortex.

M00Q3 Write about the course, branches and distribution of the maxillary nerve.A98Q4b Describe the extracranial course and distribution of the mandibular nerve.J97Q4a Describe briefly the extracranial course and distribution of the mandibular

nerve.A97Q5a Describe the extracranial course and distribution of the maxillary nerve.J96Q5b Give an account of the location, connections and distribution of the

pterygoid ganglion.M96Q4b Describe briefly the relations of the cervical sympathetic trunk and

ganglia. Give an account of the connections and distribution of the superior cervical sympathetic ganglion cells.

A95Q5b Give an account of the distribution of the superior cervical sympathetic ganglion cells.

M94Q5a Give an account of the intra- and extracranial course and branches of the facial nerve.Name the nuclei/ ganglia associated with various branches.

M93Q4b Give an account of the location, connection., and distribution of the pterygopalatine ganglion.

M92Q2b Describe the extracranial course and distribution of the facial nerve.M91Q2a Describe the extracranial course of the hypoglossal nerve (including

relations and distribution).

15. Lymphatic Drainage

M89Q5a Describe the lymphatic drainage of the head and neck.M86Q2b Write briefly on the lymphatic drainage of the head and neck.J83Q5a Give a brief account of the lymphatic drainage of the head and neck.

16. Scalenus Anterior Muscle

M01Q5 Describe the attachments and relations of the right scalenus anterior.A97Q4b Describe the attachments, actions and relations of the scalenus anterior

muscle.A95Q4b Give an account of the gross anatomy of the scalenus anterior muscle.

17. Miscellaneous

M07Q2 A patient is to undergo removal of lymph nodes close to the carotid sheath. This will require the sternocleidomastoid muscles to be freed from the deeper structures. (a) What are the deep relations of the sternocleidomastoid? (30%) (b) List four cranial nerves close to the carotid sheath. What structures are supplied by these nerves in the head and neck? (40%) (c) Describe the actions of the sternocleidomastoid muscles, acting individually,

13

ANATOMY and, together. (30%)M05Q2 Describe the face in terms of its

b.muscles of facial expressionsc.its develeopment from the pharyngeal arches

M03Q4 With respect to intraocular and extraocular muscles:(a) Describe their roles in the normal functions (movements) of the eye.(b) Outline the innervation of these muscles.

M01Q6 Give an account of the arterial supply to the brain, including the major branches and their distribution.M01Q1 A patient’s eye movements are being examined for complains of ‘double vision’.

(a) What are the extraocular muscles and how do they produce normal eye movements?

M00Q1 Give an account of the attachments, relations and actions of the leftsternocleidomastoid muscle.

A99Q4 Give an account of the(a) attachments,(b) actions, and(c) relations of the sternocleidomastoid muscle.

J98Q4a Give an account of the scalp under the following headings:i) Extent and layersii) Arterial blood supplyiii) Nerve supply

A98Q5a Describe the deep structures exposed on complete removal of the stermocleidomastoid muscle. What nerves are at risk of being damaged and what are the functional deficits resulting from loss of the muscle?

M93Q5a Give an account of the attachments, relations, innervation and actions of the

sternocleidomastoid muscle.J92Q1a Describe the gross anatomy of the scalp.J91Q5a Name the extraocular muscles, their actions and innervation.

14

BIOCHEMISTRY

1. BUFFERS

Mar08A1 a) Name the 3 different buffer systems found in saliva (3m)b) Explain the mode of action of the most effective buffer system in

stimulated saliva. (7m)

Mar07A1 Explain why proteins are important buffers in the body, and in particular, what makes hemoglobin one of the most effective buffer.

May06A1 How does the (a) ratio (b) concentration of the weak acid HA and its conjugate base A- influence its buffering capacity?

Mar06A1 Explain why proteins are(a) generally poor buffers at pH 7.5 (5 marks)(b) easily denatured at either acidic or alkaline pHs (5marks)

May05q2 Three phosphate buffers (H2PO4- / HPO4-2 , pKa=6.8) can be prepared by mixing a 1M solution of NaH2PO4 and 1M solution of Na2HPO4 in the following ratio:Buffer 1M NaH2PO4 1M Na2HPO41 10 902 50 503 90 10a) which is the best buffer? Explain your answer. (4marks)).b) Which buffer is the most effective against the addition of a base?

(3marks)c) Which buffer is the most effective against the addition of an acid? (3

marks)

May04A1 a. Illustrate the ionisation of phosphoric acid ( H3PO4) by means of and equation, and indicate which of the steps has a pKa of 2.14, 6.80 and

12.40b. What is the pH of the resulting solution when 500ml of 0.1M

sodium hydroxide is mixed with 500ml of 0.2M sodium dihydrogen phosphate?

A03A1(a) What is a buffer? How do buffers work?(7 marks)

A03A1(b) Name three systems that can act as buffers in cells and biological fluids.(3 marks)

J02A1 a. Explain why some amino acids such as alanine are good buffers at pH 2.5 and 9.5 only. (3 marks)

b. Which amino acid found in a protein could act as buffer at pH 7.4? (3 marks)

c. Based on the answers in (a) and (b), explain the buffering capacity of proteins at pH 7.4. (4 marks)

M02A1 The pKa values for phosphoric acid (H3PO4) are 2.2, 6.8 and 12.3. a. Write the equilibrium equations for the ionization of phosphoric acid and assign the pKa value of each of the ionization step. (6 marks) b. What are the predominant ionic species at pH 1, 4, 9 and 14? (4 marks)

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M01A2 Explain why the carbon dioxide-bicarbonate buffer (pKa = 6.1) is an effective buffer at pH 7.4

J99A2 What is the pH of a solution containing equal volumes of (a) 0.1 M Glycine and 0.05 M NaOH, (b) 0.1 M glycine and 0.05 M HCL? (pKa of the ionising groups of glycine are 2.3 and 9.6 respectively).

J98A6 Explain why bicarbonate is an effective physiological buffer.

J97A1 What is the pH of each of the following solutions consisting of:a) An equal volume of 0.05 M sodium acetate and 0.1 M acetic acid (pKa

= 4.78)b) An equal volume of 0.2 M glycine and 0.1 M sodium hydroxide (pKa of

-amino group of glycine = 9.8)?

M96A1 Explain why the bicarbonate (HCO3/H2CO3) buffer system (pKa 6.1) is an effective physiological buffer at 7.2.

J95A1 Explain why giving an intravenenous infusion of sodium bicarbonate solution to a patient with acidosis is more effective than giving a solution of sodium acetate of the came pH and concentration although the pKa of H2CO3 (HCO3+ H+) is 3.8 while the pKa of acetic acid CH3COOH (CH3COO+

H+) is 4.8.

J94A1 A solution of formic acid is titrated with a solution of sodium hydroxide. Explain the significance of the major features of the titration curve.

M94A1 Define buffering capacity. State 2 factors which affect buffering capacity.

J93A1 What is a buffer? Derive the Henderson-Hasselbalch equation and discuss its significance for buffer systems.

J92A1 Explain clearly why the ratio of conjugated acid and their concentrations are important properties of a buffer in determining its buffering capacity.

M92A1 State the Henderson-Hasselbalch equation. What is the pH of a colution containing 0.5 m glycine and 0.25 M sodium hydroxide given the pKs of the –COOH and –NH groups of glycine are 2.4 and 9.6 respectively.

M91A1 The conjugated acid-base pair of CO/HCO has a pKa of 6.1 but it is an effective physiological buffer at pH 7.4. Explain.

M90A1 What effect will a high PCo2 have on the following:a) Arterial pHb) Renal reabsorption of HCO3-

c) Plasma HCO concentration?Give reasons for your answers.

2. ENZYMES

Mar08A3 Give an example of the use of enzymes for each of the following:a) diagnosis of a disease or medical condition (5M)b) treatment of a disease or medical condition (5M)

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Mar08A10 Inhibition of the enzyme thymidylate synthase is considered as an option for the treatment of cancer including oral cancer. Briefly exaplint eh principles underlying this treatment.

Mar07A3 Define the terms “allostery” and “zymogen”. Describe briefly how enzymatic

activities are controlled using these concepts.

May06B3 A student carried out kinetic studies of an enzyme reaction in the absence or presence of 1mM of an inhibitor (X). The results of the experiment are given below:

[S] mM 1 2 5 10Vo uM/min -X 1.43 2.22 3.33 4.00

+X 0.71 1.11 1.67 2.00

(a) Determine the Vmax and Km in the absence and presence of the inhibitor.

(b) Briefly explain the type of inhibition.

May06A3 Define the terms “allostery” and “ cooperativity”. Describe briefly using this concept, how the activities of enzymes are regulated. In cells.

Mar06A3 Using allppurinol as an example, explain how the design of some drugs is based on the concept of enzyme inhibition.

M05Q4 A) You came across an old biochemistry textbook and found a statement in the introductory paragraph on enzymes: “all enzymes are proteins which catalyse reactions” Do you agree with this statement? Explain your answer. (5 marks)B) Why are proteases secreted as catalytically inactive forms? Give example (3 marks)

May05Q3 Give 4 advantages that enzyme have compared to inorganic catalysts.May04A3 A multi-step metabolic pathway is shown as

A B C D E Enzy-1 Enzy-2 Enzy-3 Enzy-4 Where A is the precursor, B,C & D are intermediates and E is the final

product. The enzymes incolved are Enzy-1, Enzy-2, Enzy-3, Enzy-4.

The final product E is found to inhibit Enzy-1. What is the term used to describe this mode of regulation of a metabolic pathway? List two advantages of this mode of regulation.

May04B4 a. Describe the term “ zymogen” and describe briefly how the enzymatic activities

of zymogens are controlled.

b. Besides zymogens, a cell utilizes other mechanism for regulating enzyme activity. List the different regulatory mechanism for the regulation of enzyme activity and describe the key features of the mechanism you have listed. (20marks)

M04A2 How can competitive and non-competitive enzyme inhibition be distinguished in terms of Km ? Illustrate your answer with diagrams of initial enzyme velocity as a function of substrate concentration.

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A03A3 Describe the concept of a coupled enzyme assay. Design an assay for measuring blood glucose using hexokinase, glucose-6-phosphate dehydrogenous, ATP, Mg2+,, and NADP+.

J02A3 Describe three different biochemical mechanisms which regulate enzyme activities

M02A3 (a) Sketch a graph to illustrate how enzyme activity is affected by temperature.

(5 marks) (b) Explain the graph in (a). (5 marks)

M01A2 List the characteristics of isoenzymes.Explain how biochemical analysis of isoenzymes in biological samples can aid in the diagnosis of a clinical condition. Illustrate your answer with an example.

M00A1 Explain briefly how the pH at the site of absorption affects the extend to which a drug is absorbed.

M00A3 An enzyme has a Km of 7mM and a Vmax of 200 micro mol per mg protein per second. In the presence of 200 mM of compound Y, the apparent Km value is 20mMbut the Vmax is unchanged.a) What is the nature of this inhibition?b) How can this inhibition be overcome?c) Sketch the Lineweaver-Burk plot for the above inhibition. Your plot

should consist of two lines corresponding to the situations with and without compound Y.

J99A3 The following reaction is catalysed by succinate dehydrogenase:COO-—CH2—CH2—COO- COO-—CH=CH—COO-

Succinate fumarateExplain the effect of malonate (COO-—CH2—COO-) on the velocity of the reaction. How can Vmax and Km be determined in the presence of a small amount of malonate?

A99A10 What would be the effects on human teeth of congenital deficiency of:a) Catalaseb) Alkaline phosphatase?Briefly explain your answers.

J98A2 Why are many proteases synthesized and secreted in catalytically-inactive forms?Illustrate your answer with two examples.

A98A2 The following data show the effect of substance A on the initial velocity of an enzyme-catalysed reaction. Plot the data in an appropriate way in order to determine its Km and Vmax values in the absence and presence of substance A. What type of inhibition is exhibited by substance A?

Substrate concentration (mM) Initial velocity (μmol product/min)In absence of A In presence of 20μ mol A

1.0 0.67 0.352.0 1.00 0.5310.0 1.67 0.87

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J97A3 Describe three different biochemical mechanisms which regulate enzyme activities in vivo.

A97A2 Name and explain the mechanism of action on an enzyme of an anticancer drug or an antimicrobial agent.

M96A3 a) Suggest and describe a colorimetric assay for measuring alkaline phosphatases activity.b) Alkaline phosphatase activity in serum is raised in liver and bone diseases, among others. Explain how (principles only) a clinical laboratory could distinguish between tissue origins of the alkaline phosphatase present in serum samples.

J95A2 Explain how investigation of the isoenzymes of lactate dehydrogenase and creatine kinase in the serum of a person who had collapsed during a marathon would help determine whether the problem was a myocardial infarction or severe skeleter muscle damage.

M95A2 Explain (a) why methanol (CH3OH) and ethylene glycol (HOCH2CH2OH) are more toxic than ethanol; and (b) why ethanol is used to alleviate the toxic effects of methanol or ethylene glycol.

J94A3 How can competitive and non-competitive inhibition be distinguished in terms of Km?

M94A3 What are the enzymes and coenzymes required for (a) the oxidation of ethanol to acetaldehyde; and (b) the removal and replacement of the amino groups from the alpha carbon of amino acids.Indicate the vitamin from which each coenzyme is derived and the functional involved in enzymatic inhibition.

J93A5Citing 2 examples, explain how the design of modern drugs is based on concepts of enzyme inhibition.

M93A4 Name 3 coenzymes. Give an example to show how each is involved in enzymic reaction.

J92A6 Explain the effects of a) pH b) temperature on protease activity.

M92A6 a) What are isoenzymes?b) How are they identified in the serum?c) Briefly discuss the usefulness of isoenzymes analysis.

M92B3 Discuss the statement that most of the B-vitamins in our diet are requiredbecause of their participation as coenzymes or prosthetic groups of enzymes. Illustrate your answer with suitable examples.

M91A6 What is the significance of the Km of an enzyme.

M90A6 Explain very briefly the differences between competitive inhibitors, noncompetitive inhibitors and allosteric effectors.

M90B2 Enzymes differ from other catalysts in having high substrate specificity.

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Describe how the specificity is achieved and some uses to which it can be put. Give examples where possible.

3. CARBOHYDRATES CHEMISTRY

Mar07A11 Describe the make-up of glycosaminoglycans, their typical features and theirfunction(s).

Mar06B2 (a) In the form of atble , state 5 differences between oxidative phosphorylation and substrate-level phosphorylation. ( 10 marks)(b) Show by means of biochemical steps how succinate can be completely oxidized by mitochondria. Explain how ATP can be synthesized in the process. (20 marks)

May04A6 What is substrate-level phosphorylation? (5marks) Illustrate your answer by means of two different biochemical reactions .

(5marks)

M03A1 (a) Name two different types of beta-sheets found in proteins, and explain their structural differences. (8 marks)(b) Which of them is more stable? Provide reason(s) for its stability (2 marks)

J02A7 Explain substrate level phosphorylation? (4 marks) Illustrate your answer with two examples. (6 marks)

M01A15 What are the structural features of hyaluronan?How do these features make hyaluronan a suitable component of synovial

fluid?

M00A13 Describe six functional roles of glycosaminoglycans.

M93A1 What is the molecular basis of optical activity? Explain how the opticalactivity of a molecule may be determined and its configuration assigned.

J92A2 State the differences in properties between the anomeric hydroxyl groupand the other hydroxyl groups in a monosaccharide.

M92A2 A naturally occurring aldohexose with a D-configuration was treated by a method that reduces aldehyde groups and gave a product that was optically inactive. Identify the monosaccharide and its reduction product. Explain why the product was optically inactive.

M91A2 What are mucopolysaccharides? Give an example and state its physiological function.

M90A2 Give an example of a glycosaminoglycan and explain how its function(s) are related to its structure.

4. CARBOHYDRATE METABOLISM

Mar07A4 What are the metabolic demands of muscle during a

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(a) 100m sprint (3M)(b) 1500m race (3M)(c) marathon? (4M)

M05QB2 a. explain the effects of a decrease in blood glucose level on fatty acid metabolism. (15m)b. what will happen if the low blood glucose level persists? (15m)

M05Q5 The consumption of glucose by heart muscle can be measured by artificially circulating blood through an isolated intact heart and measuring the concentration of glucose before and after the blood passes through the heart. If the circulating blood is deoxygenated, heart muscle consumes glucose at a steady rate. When oxygen is added to the blood, the rate of glucose consumption drops dramatically, and then continues at the new, lower rate. Why? (10 Marks)

May05Q8 The concentration of glucose in the blood is maintained at approximately 5mM. However, the concentration of free glucose inside muscle cells is much lower.a)Why is the concentration of glucose so low in the cell?b)What happens to the glucose upon entry into the cell>? (5 marks)

May04A8 A newspaper advertisement claimed that the most popular milk brand in Singapore is XX brand which is high in calcium and protein, but low in fat and in particular , lactose. The reason given for the popularity of low-lactosemilk is that some adults commonly Asian , suffer from abdominal fullness , bloating , cramps , pain or profuse watery diarrhoea upon drinking fresh milk , which is

avoided if they switch to low-lactose of lactose-free milk. Explain.

May04A9 An infant is admitted to the hospital with suspected glycogen-storage disease. Laboratory investigation revealed that the infant’s liver glycogen has abnormal structure with fewer number of unbranched chains compared to normal

glycogen. Which enzyme defect would you suspect to be causing the problem and how does the defect cause the formation of abnormal glycogen structures.

M04A3 In developing countries , infant mortality arising from severe diarrhoea is very

high. The UNICEF/Who oral rehydration therapy is very successful in reducing mortality. Researchers found that the most successful recipe for oralr ehydration includes sodium salts and glucose in near equimolar concentrations. Explain how water , sodium and glucose uptake is connected.

J03A6 Why does exercise training cause muscles to produce less lactate than untrained muscles for the same amount of exercise?

A03B1 Discuss how glucose homeostasis is maintained during the fasting up to approximately 40 days.

J02A4 During fasting, virtually all the glucose reserves are consumed in the first day. The brain requires glucose to function and adjusts only slowly to

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other energy stores. Explain how the body supplies the glucose required by the brain.

M02B1 Fatty acid biosynthesis takes place in the cytosol of eukaryotic cells and the major control point for the regulation of this pathway is acetyl-CoA carboxylase. a. Which reaction of fatty acid biosynthesis is catalysed by acetyl-CoA carboxylase? (4marks) b. How are the carbon fragments generated in the mitochondria made available for use in fatty acid biosynthesis? (8 marks) c. How is the activity of acetyl-CoA carbosylase regulated? (10 marks) d. What are the differences between the pathways of fatty acid β-oxidation and fatty acid biosynthesis? (8 marks)

M02A7 Patients with Von Gierke’s Disease (glycogen storage disease Type 1) lack glucose 6-phosphatase. Explain why two prominent symptoms of this disease occur: fasting hypoglycemia and lactic acidosis.

M01A10 What are the consequences, in children, of a diet very poor in protein but containing amounts of carbohydrate?

M01A5 Explain how the Cori cycle enables glycolysis to proceed in skeletal muscle during vigorous exercise.

M01A5 A sample of liver tissue was obtained from a patient believed to be deficient in one of the enzymes of carbohydrate metabolism. A homogenate of the liver had the following characteristics: (1) it degraded glycogen to glucose 6-phosphate, (2) it was unable to synthesize glycogen from any sugar or to utilize galactose as an energy source, and (3), it synthesized glucose 6-phosphate from lactate. Identify, from the list below, the enzyme that is deficient in the liver of this patient:

(a) glycogen phosphorylase(b) fructose 1,6-bisphosphatase(c) UDP-glucose pyrophosphorylase

Give reasons for your choice.

M00A5 Give three reasons why it is important that gluconeogenesis is not the exact reverse of glycolysis.

J99A5 A research scientist was growing some cells in a CO, atmosphere in order to measure the rates of lactate production and glucose utilization by the cells

under an anaerobic environment. Late one evening, his student discovered that the CO, gas tank was empty.

The student replaced the gas tank but unfortunately, he used a tank thatcontained oxygen. Predict and explain what might be the scientist's results with this new environment.

A99A3 Explain why it is important for people to be tested for glucose-6-phosphate dehydrogenase (G6PD) deficiency before they are givenantimalarial medication. Why are the effects of G6PD deficiency confined to red blood cells with no pathological consequences seen in the liver?

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A99B 1 Write an essay on the maintenance of blood glucose levels under fed andfasting conditions.

J98A3 Give 3 metabolic fates of pyruvate in normal mammalian cells? What are the conditions that determine the fate of pyruvate?

A98A3 A young Singaporean boy spent his holidays in an orchard in Australia where he helped in picking fruits. Several days later, he became jaundiced and very sick. Upon admission to a hospital the following findings were made. In addition to the expected hyperbilirubinaemia, the boy is hypoglycaemic and had markedly elevated circulating fructose and lactic acid concentrations. Further history-taking revealed that during harvest, he had eaten many more fruits than he had ever eaten before. What do you think were the biochemical causes of the elevated fructose and the hyperlacticacidaemia?

A98B2 Discuss the regulation of glycogen metabolism by allosteric modulators and by hormones.

A97B2 There are two children, Ah Huay (6 weeks old) and Ah Seng (2 years old). Ah Huay was well until recently but has not been thriving since her parents lengthened the time between feelings. She wakes frequently and is cranky but calms down with feeding. Her abdomen is protruding more and more. On the other hand, Ah Beng is fine during the day but wakes up and cries very early in the morning before anyone else in the house is awake unless he is fed during the night. The doctor who examined Ah Beng suspects an inherited defect in hepatic gluconeogenesis.a) What is wrong with Ah Huay?b) What is the most likely biochemical reason for her frequent waking and

crankiness?c) What could be the cause of her protruding abdomen?d) What advice would you give her parents to try to prevent her

symptoms?e) What levels of fatty acids, ketoacids, lactate, alanine and glucose

would you expect to find in Ah Beng's blood sample taken i)just after a meal and ii) long after a meal?

f) What are the essential metabolic differences between Ah Buoy and Ah Beng concerning the timing of their symptoms?

A97A3 Would a woman who suffers from lactase deficiency be able to breastfeedher baby, since she would not be able to tolerate milk or other dairy

products? Explain your answers.

J96A3 How is phosphofructokinase-1 regulated?

M96A5 What is the differences between hexokinase and glucokinase that ensure that glucose is properly apportioned between the muscle and the liver?

J95A3 Some anti-malarial drugs are known to cause hemolytic anemia in susceptible individuals with an enzyme defect in the pentose phosphate pathway. Explain why red blood cell lysis whereas the enzyme defect does not have any physiological consequences in the liver or muscle.

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J95B2 Glucose-6-phosphatase is at the cross-roads of 3 metabolic pathways in liver cells. Name the pathways and describe one of them in detail. Discuss theconditions that determine which pathway will prevail.

J94A4 Explain which metabolic intermediate(s) will accumulate when each of thefollowing is added to cell-free extracts capable of glycolysis:a) fluoride, which inhibits enolaseb) an inhibitor of lactate dehydrogenasec) an inhibitor of pyruvate kinase

M94A5 a) When there is a deficiency in acetyl CoA carboxylase in the liver, how can a high carbohydrate diet increase the excretion of short chain fatty

acids.g) In what clinical condition would a bite acid-binding drug be given?

Explain what benefit could be gained by this treatment.

J93A3 What are the functions of aerobic and anaerobic glycolysis?

M93A5 Although animals cannot synthesize glucose from acetyl CoA, 14C-labelled acetate fed to a rat results in the appearance of radioactive label in the muscles lycogen. Account for this observation.

M93B1 Describe how glycogen synthesis and breakdown occur in liver cells. Briefly explain the phenomena of fasting hypo-lycaemia and lacticacidemia in glycogen storage disease type 1 (Von Gierke's Disease).

M92A7 Briefly explain how the regulation of glycogen metabolism helps in the maintaining

blood glucose concentration.

M91A8 Explain why there is an accumulation of lactic acid during vigorous exercise.

M91B1 During 24 hours without food, a subject's liver glycogen content fell from 100g to 50g. Describe the pathway which then be used to maintain blood glucose levels. Include details of the precursors and the location of the pathway.

M90A8 Draw a diagram showing the malate-aspartate shuttle. What is the significance of this shuttle?

5. AMINO ACID CHEMISTRY

Mar08A2 The 3pKa of the free amino acid lysine are : 2.18 (alpha-carboxyl group); 8.95 (alpha-amino group) and 10.53 (R-group/amino group) respectively.a) What would be the charge of lysine at pH 1, 7 and 12? (6M)b) If lysine is incorporated into a polypeptide, what would be its charge at pH1?(2m)c) At what range of pH will lysine be expected to have no net charge? (2M)

Mar08A8 (a) What are ketone bodies? (2m)(b) How are ketone bodies produced in vivo? (4M)(c) How are ketone bodies metabolized? (4M)

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Mar07A2 Which of the following statements regarding proteins are correct? For each incorrect statement, provide the correct version. (a) The α-helix can be composed of more than one polypeptide chain. (2M)

(b) β-sheets exist only in antiparallel form. (2M)(c) In a tertiary protein structure, hydrophilic R groups are on the surface

while hydrophobic R groups are buried inside the protein. (2M)

(d) Domains are a type of secondary structure. (2M)(e) The α-helix is stabilized primarily by ionic interactions between the side chains of amino acids (2M)

May06A2 Explain why the amino acid proline is commonly found in B-turns but not in ǻ helices of proteins.

M05Q3 What types of amino acids are found on the surface of a water soluble globular protein? Explain clearly how a change in pH from pH 7.4 to either pH 2.0 or pH 10 can denature such a protein. (10 m)

May05Q1 What are the buffering groups of amino acid histidine? Explain why proteins containing many histidine residues can function as good physiological buffers. (10M)

May05Q1 What do you understand by the terms “secondary structures” and “domains” of proteins? Illustrate your answer with a suitable example for each.

May04A2 Explain clearly how covalent bonds play a major role in stabilizing the structure of fibrous proteins such as collagen.

M04A1 Explain (a) how proline disrupts an α-helix, and (b) why the amino acid sequence of proline-glycine (Pro-Gly) is commonly found in β-bends of protein structures.

M03A8 (b) Explain why a protein becomes less soluble and often precipitates from solution when it is denatured. (7 marks)

J02A2 Explain (a) protein denaturation and (b) how high temperatures and pH extremes could induce protein denaturation.

M02A2 With respect to the structure of the amino acid, glycine, explain how it a. stabilizes the triple helix of collagen. (5 marks) b. destabilizes the α-helices that are present in many proteins (5 marks)

M01A15 What is the role of procollagen peptidase in the formation of collagen fibrils?

Explain why the active forms of procollagen peptidases are absent withincollagen-secreting cells.

M01A1 What roles of hydroxyproline and γ–carboxyglutamate play in the function of collagen and prothrombin respectively?

M00A7 For humans, give the immediate precursors and the enzyme involved in the biosynthesis of

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(a) glutamine(b) gamma-aminobutyrate (GABA)(c) putrescine

M00A2 What type of amino acids are found on the surface of a water-soluble globular protein? Explain clearly how pH changes can affect the stability of such a

protein.

J99A1 Explain why amino acid residues that are far apart in the primary sequence of a protein can be close to each other in its tertiary structure.

A99A1 Explain how changes in pH alter the confirmation of proteins.

A99A2 Suggest the effects of each of the following substitutions on the physiology role of chymotrypsinogen:

(a) Arg 15 --> Ser 15(b) Cys I --> Set 1?

J98A1 Explain why fibrous proteins are well-suited to serve structural functions.

A98A1 Define protein denaturation. Explain the differences between denaturation and

renaturation of ribonuclease and insulin.

J97A2 List the main characteristics of globular proteins and explain how hydrophobic

interactions contribute to their stability.

A97A1 What is a conjugated protein? Give an example and outline its biochemical function.

A97A12 Describe briefly the major component of non-collageneous protein in dentine.

J96A1 Give two methods by means of which one could separate an acidic amino acid from a basic acid. For each of these explain the underlying principle of the method.

M96A2 Explain how the structures of fibrous proteins are adapted for their specialised functions. Illustrate your answers with examples.

M95A1 Define protein denaturation. Explain why and when insulin was subjected todenaturation and then renaturation conditions, it regained only a few percent of its original activity.

A95B2 Using haemoglobin as an example, describe the structural organization ofproteins.

J94A2 What is the basis of the classification of amino acids? Give one example for each class of amino acids.

J93A2 Explain the differences between non-polar, polar, uncharged and charged amino acids.

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M93A2 Explain how it is possible to separate lysine, glycine and glutamic acid? Name a suitable technique.

M93A3 Describe the effects of the following on protein stability:(a) hydrophobic forces, (b) disulphide bonds, (c) hydrogen bonds.

J92A5 Name the following amino acids. State briefly what you know of the importance of each in protein structure:

NH(a) HS.CH.CH COOH

NH(b) NH.CH.CH.CH.CH.CH. COOH

(c) HC CH HC CH COOH

NH

M92A5 What is meant by the following terms used to describe protein molecules?a) primary structureb) secondary structurec) tertiary structure

M91A5 At physiological pH which amino acid residue in the oligopeptide shown below would be positively charged?

gly-glu-asn-gln-leu-lys-aspwhat is the net charge on this polypeptide when subjected to electrophoresis at physiological pH? Towards which electrode would this oligopeptide migrate?

M90A5 Explain the principle underlying the use of ammonium sulphate in thefractionation and purification of proteins/

6. AMINO ACID METABOLISM

Mar08A6 Give an example of an inherited disorder that affects the urea cycle. (2m)What is the expected consequences resulting from such a defect? (8M)

May06A7 With reference to amino acids, give a named ecample for each of the following reactions:(a) decarboxylation(b) transamination.

May06A11 You have decided to work out this year and are going regularly to the gym to increase and shape your muscles mass. As your muscle mass and strength increase something else must be reshaped as well to cope with the new situation. Which system (besides perhaps some more vascularisation) is affected and name the cell types and enzymes that will be involved.

May06B1 Discuss the possible metabolic fates of the carbon skeletons of amino acids.

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Mar06A4 Briefly explain how a normal healthy individual is able to prevent excessive build up of ammonia produced during metabolism of amino acids.

M05Q6 Some amino acids are important precursors of physiologically important amines. Provide two examples of such amines and show how each of them may be derived.

May05Q4 With reference to humans , explain the concept of “amino acid pool and turnover”

May04A12 Give an example of an amino acid which is both glucogenic and nonessential, and explain why you consider it as such.

M04A6 Explain why a lot of alanine appears to be moving via the blood stream from muscles to liver.

M03A8 (a) Name 3 ways by which proteins may be denatured. (3 marks)

M03B1 Discuss the consequences of a genetic defect in one of the enzymes of the urea cycle.

A03A4 Explain “transdeamination” of an amino acid by providing suitable exaample

M03A3 Explain the term “glucogenic” with respect to an amino acid and provide an example to illustrate your answer.

J02A10 Briefly describe how methotrexate and dFUMP inhibit biosynthesis of deoxyribonucleic acid.

J02A6 a. Explain the terms (i) amino acid pool (3 marks) (ii) amino acid turnover (3 marks)

b. Name the conditions in which amino acids are excreted in the urine? (4 marks)

M02A9 Describe the metabolic fate of hydroxylmethyl glutaryl-CoA (HMG-CoA) in

a. mitochondria (5 marks) b. cytosol (5 marks)

M02A8 If an amino acid is catabolized to acetyl-CoA, would you consider the amino acid as glucogenic or ketogenic? Explain your answer.

M02A4 By means of biochemical reactions, show how the following enzymes could reduce the reactive oxygen species in the body: a. catalase (3 marks) b. superoxide dismutase (4 marks) c. glutathione peroxidase (3 marks)

M01A6 What is the function of gamma-amino-butyric acid (GABA)?How is it synthesized and degraded?

M01A6 What is the metabolic significance of the reaction catalyzed by the glutamate dehydrogenase?

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J99A6 Explain how alanine can be deaminated in the human body.

J99B3 With reference to humans:(a) discuss the possible fates of dietary L-glutamic acid.(b) Explain briefly how excess nitrogen is excreted from the body.

A99A5 Kitty, a pet kitten, requires a diet containing L-arginine to prevent ammonia toxicity and possibly death. Explain the need for the inclusion of arginine in Kitty's diet.

J98A4 Give three biochemical functions of L-glutamate.

A98A5 Your patient is believed to have a defect in the urea cycle. You finally come to the conclusion that he is suffering, from citrullinaemia based upon certain

biochemical findings. Justify how you arrived at your diagnosis.

J97A5 Name the immediate precursors and the enzyme involved in the biosynthesis of:

a) histamineb) gamma-aminobutyratec) putrescine

A97A4 Consider the following metabolic pathways:a) Name the enzymes and coenzymes involved in steps A, B and C.b) lf there is a defect in urea synthesis, how might the body attempt to

deal with the increased load of ammonia (or ammonia ions) ?

J96A6 Describe the glucose-alanine cycle and explain its role in metabolism.

M96A7 Briefly describe the importance of urea synthesis in humans.

J95A5 Decarboxylation of some amino acids or their derivatives yields physiological important products. Give two examples of these products and show how they are formed.

J95B4 Describe the importance of glutamate and glutamine in mammalian metabolism.

M95A6 Give the reactions of the pathway of urea synthesis in man that involve the participation of ATP.

J94A6 Describe two ways by which oxidative deamination of amino acids takes place in the mammalian liver.

J94B4 Discuss the different possible metabolic fates of the nitrogen atoms of ingested proteins.

M94A7 Name 1 neurotransmitters that are derived from the metabolism of amino acids in man, Show how one of these may be synthesized in the body.

M93A7 How is urea cycle regulated?

M93B1 Discuss the metabolism of aromatic amino acids and diseases which areassociated with error in this metabolism.

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J92A9 Outline the biosynthetic pathway of epinephrine and name the enzymes involved.

M92A9 Briefly describe the biochemical functions of glutathione.

M91A9 Give an example of an inherited disorder of the urea cycle. State clearlythe metabolic defect and the consequence(s) of such a defect.

M90A9 Name two physiological important primary amines derived from thedecarboxylation of amino acids or their metabolises. For each, give the

enzymic reaction(s) leading to its formation.

7. LIPID CHEMISTRY

Mar07B1 Discuss the biochemical principles for the statement “Fats can by synthesized from carbohydrates, while, in general, they cannot be used for the net synthesis of carbohydrates in animals”.

Mar06B3 (a) Discuss the role of lipoprotein lipase in the metabolism of lipo proteins.(15 marks)(c) Predict the plasma lipid profile of a patient with a deficiency in

apolipoprotein C – II ( 10 marks)(d) How different is this patient’s plasma lipid profile from another patient

with a deficiency in bile salts? ( 5 marks)

M05Q7 Describe the effect(s) of a deficiency in apolipoprotein B-100 (apo B-100) on the metabolism of low density lipoproteins. (8 marks)What will be the biomedical consequence(s) of such a deficiency? (2 marks)

M00B5 Lipids can be transported in the vasculature only if they are safely packaged and equipped with signals to ensure their assimilation into tissues requiring them. Describe the mechanisms in the human body whereby there processes are accomplished.

M00A6 Explain briefly the importance of the distinction between n3(w-3) and n6(w-6) fatty acids.J93A4 Describe the biochemical reactions which involve the carboxyl group of fatty acids. Briefly discuss the biological significance of one of these reactions.

J93A6 What is the nature and role of serum high density lipoprotein?

J92A4 Explain how the structures of phospholipids makes liposomes formation possible.

M92A4 Point out the essential chemical characteristics of (a)a saturated fatty acid (b)a

triglyceride (c) cholesterol.

M91A4 Explain the termsa) saponificationb) amphipathisc) iodine number

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M90A4 What are the functional roles of phospholipids and cholesterol in biologicalmembranes?

8. LIPID METABOLISM

Mar07A5 Lipoprotein lipase is deficient due to a genetic mutation. How would this affect

the metabolism of plasma lipoproteins?

Mar08B3 Obesity is a global epidermic and poses severe medical and esthetic problems.(a) Why is type-2 diabetes aggravated by obesity?(b) Name one other disease that is associated with obesity.(c) Which tissue secretes leptin?(d) In which organ are leptin receptors located?(e) What physiological roles does leptin play?(f) How does leptin induce appetite suppression?(g) What would be the effect of loss-of-function mutations of leptin receptor?(h) Explain why leptin administration to most grossly obese individuals result in only marginal reduction of appetite and obesity(i) Name a druf that is approved by FDA for appetite reduction and state its mode of action.

May06A6 Describe how intracellular cholesterol homeostasis is maintained following the uptake of LDL by cells.

May05Q6 a.What is the role of lipoprotein lipase in fat metabolism? How does it become activated? (5 marks)b. state the role of carnitine and citrate in fatty acid metabolism. (5 marks)

May04A10 Compare and contrast the biosyntheses of triacylglycerol in liver , adipose tissue and small intestine.

May04B3 Discuss the role of lipoproteins in the transport and storage of lipids and explain what happens when lipoprotein lipase is deficient in an individual.

M04A5 Outline the metabolism of plasma very low-density lipoproteins (VLDL).

M03B2 Why do plasma cholesterol levels depend on the quantity of functional LDL receptors? A patient was found to have high plasma levels of cholesterol. How may the patient’s plasma cholesterol level be reduced? Explain the biochemical basis of the treatment.

A03A5 A substance inhibits the oxidation of palmitoyl-CoA by isolated mitochondria but has no effect on the oxidation of palmitoylcarnitine. What is the most likely biochemical step that is inhibited by this substance? Explain your answer.

M03A2 What will happen to the concentration of chylomicrans in human plasma if an individual switches from a diet rich in fat to a low fat vegetarian diet? Explain your answer.

J02A5 Compare the roles of very low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL) in transport of lipids.

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M01A9 What is the importance of β-oxidation for the provision of energy to humans?

M01A7 What is the role of high density lipoproteins in lipid metabolism and transport?

M00A14 When you are about to administer a general anesthetic to a patient, you noticed

that he is rather plump. Since the dosage has to be adjusted for body fat, and

his weight is 86 kg with a height of 160cm. Do you conclude that he is indeed

obese? Provide an explanation for your answer.

A99A6 Explain why an abnormality in the ratio of unsaturated to saturated fatty acids in

the red cell membrane can lead to haemolytic anaemia.

A99B2 Write an account of the structural and metabolic importance of cholesterol and

indicate its importance in certain diseases.

J98A7 Explain the link between the enzyme lecithin cholesterol acyl transferase and the

progress of arterial disease.

A98A4 Explain the role of high density lipoproteins in lipid transport.

A97B4 Discuss the concept of "reverse cholesterol transport and indicate how itsoperation might contribute to a lowering of serum cholesterol.

J96A5 Slimming preparations in the health food stores in blood lipids resulting from a)

over synthesis of alipoprotein B 100, b) deficiency of alipoprotein AI, c) adeleterious mutation in the region coding for the substrate-bonding site inlipoprotein lipase.

M95A4 "Cot deaths" (sudden deaths during the night in young children) have been

attributed to medium chain fatty acyl dehydrogenase deficiency.It has also been noticed that such deaths occur more often in Western

than inAsia populations. In the former, as a social habit. children are put to bed in

theearly evening and remains there till morning.In the latter, children are allowed to stay up late and join in the family activities. How could these facts explain the greater prevalence of cot deaths in the West?

J94AS What metabolic processes would be defective as a result of a deficiency of the

following enzymes:a) HAG-CoA reductase.b) Carnitive transferasec) Citrate synthase.

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J94B2 Discuss the role of the lipoproteins in the transport and storage of lipids and

explain what happens when lipoprotein lipase is deficient in an individual.

M94A4 Acetyl CoA activates pyruvate carboxylase. How does this activation contribute to the recovery of energy from fatty acids?

J93B2 Explain the roles and importance of fatty acids in metabolism.

M93A6 Starting from the point where digestion has occurred, explain the pathway by

which an exogenous triacylglycerol (triglyceride) is assimilated by the tissues

which utilize it.

J92A8 Describe briefly the function of each of the following in lipid metabolism:a) bile saltsb) acyl carrier proteinc) carnitive

M92A8 What are ketone bodies? Explain briefly a) how they are formed and b) why they

accumulate in starvation or untreated diabetes mellitus.

M91 B2 Compare the processes of fatty acid oxidation and biosynthesis. Emphasize the

differences and comment on the energy yields and requirements in the two

processes.

M90A10 Describe the functions for the following in lipid metabolism:a) bile saltsb) "clearing factor"c) hormone-sensitive lipase

M90B3 What is the importance of fat in the human diet? Discuss the problemsassociated with the excessive intake of carbohydrates and fats in our diet.

9. NUCLEIC ACID CHEMISTRY

J98A10 Describe the symptoms and biochemical manifestations associated with gout. How does allopurinol help to alleviate gout?

A97A9 Azidothymidine (AZT) is used to treat patients who have been infected with the HIV-1 virus. Briefly explain the biochemical action of AZT.

J93A7 Explain the differences between nucleosides, nucleotides and polyneeleotides.

J93A9 Describe the macro molecular composition and role of ribosomes in eukaryotic protein synthesis.

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J92A3 List the chemical components that make up DNA. Name the linkages between these chemical components. Explain how the strands of double stranded DNA interact with each other (chemical structures not required).

M92A3 Give the following sequence of a double stranded DNA molecule which istranscribed by RNA polymerase, write the nucleotide sequence of the

messenger RNA transcript assuming that there is a start cation (AUG) in the transcript.5 ... ATGAATGCTTGCTGT ... 33 ... TACTTACGAACGACA ... 5

If this mRNA continues to code for an uninterrupted sequence of 999 nucleotides before it reaches a stop codon, how many amino acids are coded for in the protein product?

M91A3 Name the various chemical components that make up DNA and RNA. Why is RNA less stable than DNA?

M90A3 Name a nucleotide found in (a) RNA (b) DNA. How would each of thesenucleotides interact with others during DNA-RNA hybridization?

10. NUCLEIC ACID METABOLISM

May06A9 Briefly discuss the importance of salvage pathways in nucleotide metabolism. ( 4 marks) A partial deficiency of one of the enzymes in the salvage pathway causes excessive production of uric acid in urine.(a) Name this enzyme ( 2 marks)(b) Briefly explain how the excess uric acid production occurs. ( 4 marks)

May06A10 Briefly describe how dideoxy nucleotides bring about inhibition of DNA synthesis. ( 5 marks)Briefly discuss their use as therapeutic agents. ( 5 marks)

M03A10 (a) Briefly describe the effects of using a specific drug to block the catabolism of hypoxanthine to xanthine (5 marks)(b) Name the enzyme involved in this catabolic step and explain the consequence of producing excess xanthine

(5 marks)

M02A11 Name the enzymes that are subjected to feedback inhibition by adenosine monophosphate (AMP) and guanosine monophosphate (GMP) during purine biosynthesis. (6 marks)Briefly explain the reasons for such inhibitions. (4 marks)

M01A12 Describe two differences between the synthesis of purines and pyrimidines.

M01A3 Identify the defective enzyme and the metabolic pathway that is associated with Lesch-Nyhan syndrome. Name a drug that would be useful in managing this disease and briefly describe its action.

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M98A8 Name 3 nucleotide derivatives that have therapeutic applications. Explain the

biochemical bases of their actions.

J95A8 What is xeroderma pigmentosum? Describe the biochemical basis for thiscondition.

M95A8 By means of a diagram, describe the regulation of deoxyribonueleosidebiosynthesis.

J94A9 Name the disease which results from a deficiency of hypoxanthine-guanine

phosphoribosyl transferase. Briefly describe the symptoms.

M94A9 By means of a diagram, outline how the biosynthesis of AMP and GMP isregulated.

11. GENETICS, GENE REPLICATION, TRANSLATION, TRANSCRIPTION AND PROTEIN SYNTHESIS

Mar08A9 In the liver, the pre-mRNA expressed from a gene produces a mature mRNA containing exon A + exon 1 + exon 2 while in the salivary gland the mature mRNA produced contains exon B + Exon 1 + exon 2.(a) Why do they think that there Is a need for the exons to make such

different combinations to form the mature mRNA in the liver and salivary gland?(6m)

(b) If you have a patient who has point mutations on the last nucleotide at the 3’ end of intron 1 and the first nucleotide at the beinning (5’end) of intron 2 (in both cases the Gs are changed to Cs) how will this affect the expression of the protein in the salivary gland? (4m)

Mar08A12 A child has cleft lip and palate, hearing loss and developmental delay. His parents show none of these conditions. What are the possible genetic and non-genetic etiologies for the child’s midecal condition?

Mar08B4 Your neighbours are a friendly couple in their midfourties. They have one daughter who is now 4years old. She looks a bit different with bluish/grayish sclera, a slightly triangular face. She is too small for her age and – you don’t see it often – she always seems to wear a plaster cast of some sort somewhere. The child is quite bright though. One day the couple was summoned to court since charges of child abuse were brought fourth. Paediatricians at LL Hospital and staff and the Enlidhtened Child Preschool found it very suspicious that the child had so many fractures. The couple is devastated and asks you for help. Elaborate on a possible diagnosis, a way to establish this diagnosis biochemically, discribe the genetic basis and the consequences from the intra to extracellular level.

Mar07B3 Describe and discuss the features of the autosomal dominant, autosomal recessive and X-linked recessive inheritance patterns in man.

Mar07A12 WX syndrome is a neurological disorder with variable severity. Scientists have

identified the WX gene mutation within the mitochondrial genome.(a) What is heteroplasmy and how does it affect disease severity? (4M)(b) What are the risks of an affected male or an affected female

transmitting the disease to offspring, and why? (6M)

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Mar07A9 The nucleotide and amino acid sequences of a messenger RNA and its translated

protein respectively are given below:mRNA: 5’ AUG UUU CAA AUU UUG GUA AGC UGA 3’Protein: Met - Phe – Gln - Ile - Leu – Val - Ser – Stop(a) If the A nucleotide in AUU codon above is deleted, briefly explain the

effectof this mutation on the translated protein. (5M)(b) Write down the sequence of the DNA that formed the template for the transcription of the mutated mRNA in (a). (5M)

Mar07A7 What is meant by the term, “RNA interference (RNAi)”? Briefly explain the mechanism of RNA interference by siRNAs.

May06A8 What is meant by the term “alternative splicing”? ( 4 marks)Briefly explain how alternative splicing of amylase mRNA takes place in cells of salivary gland and liver. ( 6 marks)

MarA15 Describe the features of autosomal recessive inheritances/transmission with respect to (a) transmission possibilites ( eg. Male to male), (b) sex distribution of affecteds and (c) probability of having an affected child. ( 5 marks)

A couple suffers from autosomal recessive hearing impairment. The husband’s condition is due to a mutation of a gene in chromosome–1 while the wife’s is caused by a mutation of a gene in chronosome – 2. What is the probability of the couple having a hearing impaired child? Explain your answer. ( 5 marks)

Mar06A7. After surgery, patients with oral cancer suffer from a dry mouth syndrome due to poor expression of an aquaporin gene, AQP5. Based on this information, briefly describe the possible ways by which symptoms of this syndrome could be alleviated.

Mar06A8. The nucleotide and amino acid sequences of a mRNA and its translated protein respectively are given below:mRNA: 5’ AUG UUU CAA AUU UUG GUA AUU UGA 3’Protein Met- Phe – Gln – Ile- Leu – Val – Ile – Stop(a) If a U to A mutation takes place in the second base of the UGG codon,

briefly explain the effect of this mutation on the translated protein. ( 5 marks)

(b) Write down the sequence of the DNA that formed the template for the transcription of the mutated mRNA.

M05Qb3 Describe three molecular biology methods that can be used to identify mutations in a genome.

M05Q12 The ‘crooked mouth’ gene was recently discovered and it was found that many individuals with ‘crooked mouth’ syndrome, which is an autosomal dominant disease, has the following mutation in this geneNormal: ……GAATCC……Crooked mouth: ……GGATCC……GGATCC is recognized by the restriction enzyme BamHI.A young man with ‘crooked’ mouth married a young woman with normal mouth and the woman have just given birth to a child with crooked mouth.

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You would like to find out if the child and the father have the above mutation in their ‘crooked mouth’ gene.a) Describe the techniques you would employ to determine if this child

had the above mutation in the crooked mouth gene. (6 marks)b) Predict the results you would expect for the child, father and mother

assuming that the father and child have this mutation. (4 marks)

M05Q8 A patient with malignant melanoma has asked you if his cancer can be treated with a drug that targets telomerase. You are aware that currently there is no such drug available.a)Explain briefly to the patient the mechanism of action of telomerase.(5marks)b)Why is telomerase an attractive target for cancer therapy? (5 marks)

M05Q6 a) Name two post-transcriptional modifications of mRNA that can occur in eukaryotic cells. (4 marks)b)Briefly explain the reasons for such modifications. (6 marks)

May05Q10 A woman has a very strong history of familial colon cancer. It is your opinion that this is likely to be a single gene disorder. She would like to undergo genetic testing to see if she has the ‘bad’ gene. In order to be able to interpret the results more accurately, it is also your opinion that you should test her mother who had colon cancer. Her mother, however, refuses to agree to genetic testing for colon cancer related genes despite multiple episodes of counselling.Should you proceed and perform genetic testing on her mother despite her refusal? Explain the basis of your decision.

May05Q8 A. Name two synthetic nucleosides that can be used to inhibit viral reverse transcriptase activity. (4 marks) B. Briefly explain their potential use in medicine. (6 marks)

May04A4 What is RNA-Dependent DNA polymerase? (4 marks) Explain its function with the help of a named example. (6 marks)

May04A5 Briefly describe the principle underlying Sanger’s method of DNA sequencing.

May04A11 A researcher would like to generate many copies of a piece of DNA containing the gene responsible for preventing gingivitis by cloning it into a plasmid vector. Flanking the gene on the DNA is the restriction site Pst1. Briefly describe

a. properties of the plasmid vector (4 marks)b. Cloning process involved (6 marks)

M04A7 Name a method that can be employed to identify the presence of SARS virus in an infected person. (4 markls)

Explain the principle underlying the method. ( 6 marks) M04A8 Briefly describe the structure and function of telomeres. M04A9 Name 2 antibiotics that inhibit protein synthesis in prokaryotes. ( 4 marks)

Briefly explain the mode of action of each of them. (6 marks)M04A12 A deaf couple are told that both their hearing impairments are autosomal

recessice conditions, but that his is linked to a gene on chromosome-1 while hers

is linked to a gene on chromosome-2.

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(a) They are told by the clinical geneticist that there is little or no risk of conceiving a hearing impaired child. Explain how the doctor arrived at this conclusion. ( 5 marks)(b) List and explain one genetic event( pre-conception of post-conception)that could lead to the child being affected by deafness due to complete loss of function of the chromosome 1 or 2 gene. ( 5 marks)

M03A6 (a) Distinguish between a prokaryotic and an eukaryotic gene (5 marks)(b) Briefly desribe the post-translational processes that take place in an eukaryotic cell (5 marks)

M03A9 Name the enzymes and other cellular components that are required for DNA replication in vivo and briefly explain the function of the enzymes.

M03A11 The “sparkling Teeth” gene was found to be 6kb long and can be digested with the EcoRI restriction enzyme to yield 1.5 and 4.5kb fragments. These fragments can then be separated by gel electophoresis. (a) Describe the principle of gel electrophoresis (5 marks) (b) What kind of gel matrix would you use to separate these fragments?

(2 marks) (c) How would you visualize the DNA fragments on the gel? (3 marks)

A03A12 (a) What are the major types of RNAs found in eukaryocytic cells? (3 marks)(b) Briefly explain the function of each of them. (5 marks)(c) What is a ribozyme? (2 marks)

A03A13 You have been provided with the following 5’-end DNA sequences of non-template strands of a normal and mutant gene encoding human haemoglobin from a molecular pathology laboratory:Normal:5’ TTAATATGCCGTACTGCCAGCTAACTGCTAAAGAACAATTT….3’Mutant:5’ TTAATATGCCGTAGTGCCAGCTAACTGCTAAAGAACAATTT….3’

(a) Identify the mutated base (2 marks)(b) What type of mutation is this? (2 marks)(c) Write down the coding sequences in both the normal and mutant (2 marks)(d) Name a disease among Asians that is associated with mutations of haemoglobin . (2 marks)(e) Briefly describe the consequence of this disease. (2 marks)

A03A14 (a) List the 4 main classical inheritance patterns in man. (4 marks)

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(b) Of these, which is the least common? (1 mark)(c) John and his sister Jane, both in their 40s, have been toothless since birth. Jane’s 2 sons and 2 daughters, all adults, are also toothless. Fortunately for John, his 2 sons and 2 daughters have normal teeth. Draw a pedigree to depict the given information, using proper symbols. (2 marks)(d) If this disorder is caused by a gene defect, what kind of disorder best explains the transmission/inheritance pattern in this pedigree, and why? (3 marks)

A03A15 “Vampire Tooth” disease has been discovered to be caused by mutation in a gene for tooth development. The mutation destroys a BamHI restriction site. To diagnose if Jeremy, who has a vampire teeth, has the mutation, the gene is first amplified and then digested with restriction enzyme BamHI.(a) Describe the process by which the “vampire teeth” gene can be

amplified. (5 marks)(b) What is the restriction site? (2 marks)(c) Describe the properties of restriction enzymes. (3 marks)

J02B2 Describe the organization of the human insulin gene and show how its genetic information is used for the production of biologically active insulin.

J02A11 Name 5 post-translational modifications of proteins that may occur in a eukaryotic cell. Briefly explain the reasons for such modifications.

M02A10 Briefly describe how mRNA is synthesized and processed in an eukaryote.M01A11 With regard to genetic linkage:

(a)What is Mendel's Law of Independent Assortment? When does it holdtrue, and when does it not?

(b)Recombination fraction θ is a good estimate of genetic distance y oversmall but not large intervals. Why?(c)A couple had a previous child with a lethal serious autosomal recessivecondition but the wife is pregnant again. Prenatal diagnosis using a

polymorphic marker that lies within the gene yielded the following results. Which markerallele co-segregates with the mutant allele in each parent and how would you counsel the parents regarding the genotype and disease status of the fetus?

M01A8 (a) Briefly describe the process of the polymerase chain reaction (PCR).(b) Give an example of an application of PCR in medicine.

M01A7 Name a nucleotide that can terminate the action of DNA polymerase. Explain its use as a therapeutic agent.

M01A1 What is (a) protein denaturation, and (b) protein renaturation?

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Explain the differences between the two process for ribocnulease and insulin.

M01A10 Describe two molecular mechanisms by which single base mutations can be induced in DNA. Illustrate your answer with suitable examples.

M01A4 (a) Explain why the excretion of stercobilin rather than urobilin reflects more closely the breakdown of haem.(b) Explain how the presence of lead in the environment can cause

anemia. (c) Describe the role of protoporphyrin IX in drug hydroxylation.

M00B4 Briefly describe the molecular organization of an eukaryotic autosomalchromosome.

M00A11 Name two potentially carcinogenic agents and briefly explain how each brings about its mutagenic activities.

M00A12 Which of the following gene mutations is most likely to affect the function of a protein?

Explain your answer.(a) Insertion of a single nucleotide near the end of the coding sequence(b) Removal of a single nucleotide near the beginning of the coding

sequence(c) Deletion of three consecutive nucleotides in the middle of the coding

sequence

J99A8 A clinical laboratory discovers an outbreak of an Escherichia coli infection in Singapore. If replication of this bacterial DNA proceeds simultaneously from 3 points of origin in its genome (4.47 x 106 base pairs) and at a rate of 750 base pairs per second at each replication fork, calculate the rate at which the

bacterium is capable of multiplying in the gut of the pat dent.

J99A10 Briefly describe the mechanism(s) that ensure the accuracy of translation in eukaryotes.

J99B 1 In relation to genes, explain(a) what governs their expression in a particular tissue and at a particular

time.(b) How their expression is regulated.(c) How dysregulation may lead to diseases.

A99A8 Define exons. What are their role(s) in gene expression?

A99A9 What is reverse transcription? With the help of an example briefly explain the process.

J98A12 Define and explain the significance of the following during DNA synthesis:a) Okazaki fragments, b) DNA ligase, and c) primer RNA.

J98A9 What governs the specificity in the initiation of transcription in prokaryotes?

M98A9 Briefly describe the phenotypic traits associated witha) Dentinogenesis imperfecta

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b) Acatalasaemia.Draw typical pedigree tables to illustrate how these conditions are

genetically inherited.M98B4 Discuss the statement that DNA is an informational molecule capable of self replication prior to cell division.

A97A 10 Primary RNA transcripts can undergo alternative splicing giving rise to different mature

mRNAs. The figure below shows a DNA with 2 different 3' splice sites.When the DNA is transcribed. two different mature mRNAs can be

obtained via alternate splicing. Based on the information in the figure, draw the followingtranscripts in your answer book:

a)b) Primary transcript,c) the same transcript in (a) after it has undergone cleavage and

polyadenylation, andd) the two mature mRNAs after splicing of the transcripts in (b).

J96A8 Compare and contrast the B and Z forms of DNA.

M96A13 Explain what is meant by the term "restriction endonuclease" and give anexample. Outline some uses for restriction endonucleases in molecular

biology.

J95A7 Compare and contrast the structure B-DNA with that of Z-DNA.

J95A9 Describe the mechanisms by which high accuracy is achieved in:a)DNA replicationb)Translation

M95A9 Describe briefly:a)the lac operon andb)RNA polymerase of prokaryotes.

M95A10 Explain what trans-acting factors and cis-acting elements are.

J94A10 Describe the initiation of transcription in prokaryotes.

J94A 11 What is meant by the following terms:i) introns and exonsii)chromosomal bandingiii)nucleic acid hybridization

M94A2 Describe the classical denaturation-renaturation experiment on ribonuclease and explain its significance.

M94A10 Describe the initiation of DNA synthesis at the origin of replication.

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M94A11 Explain how staining or banding methods for karyotyping human chromosomes are used in detecting genetic abnormalities.M93A8 a) Suppose that in an extraterrestrial organism, the amino acids are coded

by doublets which may be any combination of the bases A, G, T and C.What is the maximum number of different amino acids that could bepresent in its proteins?

c) It was once considered a possibility that the genetic code might be anoverlapping code of the following type: the codons in the base

sequenceCATCATCAT ... would be CATATCTCACAT...How was this hypothesis affected by the observation that mutant

proteins usually differ from wild-type proteins by a single amino acid?

J92B3a Write an essay on DNA-dependent RNA synthesis in bacteria.

M92A11 Describe the formation of arninoacyl-tRNAs.

M91A10 Explain the functions of the DNA template in messenger RNA(mRNA)synthesis.

M90A11 Tetracycline, erythromycin and chloramphenicol are powerful inhibitors ofbacterial growth. For the treatment of internal bacterial infections in

humans, only the first two are widely used while chloramphenicol is rarely used. Explain these facts from your knowledge of protein synthesis.

12. INTEGRATION OF METABOLISM

May06A5 What changes in hormone levels and fuel metabolism occur during an overnight fast?

May05B2 A Child was brought to the clinic with nausea, vomiting and symptoms of hypoglycaemia: sweating, dizziness, and trembling. It was reported that these attacks occurred shortly after eating fruit or cane sugar. The child was an only child who had been breast-fed, during which none of these symptoms were evident. The clinical findings included some cirrhosis of the liver and a normal glucose tolerance test. The urine was negative for glucose but positive for fructose. A fructose tolerance test using 3g fructose/m2 of body surface was given intravenously in a single, rapid push. Within 30 minutes the child displayed symptoms of hypoglycaemia. Blood glucose analysis confirmed this and revealed that the hypoglycaemia was greatest after 60-90 minutes.Fructose concentrations reached a maximum (3.3 mM) after 15 minutes and gradually decreased to zero in 2.5 hours. Inorganic Phosphate concentrations fell by 50% and AST (aspartate transaminase) and ALT (alanine transaminase) elevation were noted after 1.5 hours. During the hypoglycaemic episode, glucagons infusion could not elevate the blood glucose concentration.

a) Explain which enzyme deficiency this child has and why the fructose concentration in the blood remained elevated for an extended period. (10 marks)

b) Explain the elevation noted for AST and ALT in the fructose tolerance test. (5marks)

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c) In the face of severely low intracellular inorganic phosphate concentrations, what explanations can be proposed for the hypoglycaemia that is not responsive to glucagon? (5 marks)

d) Why are the symptoms of hypoglycaemia not found in essential fructosuria type 1? (5 marks)

e) What would be the consequence of a further deficiency of phosphofructokinase in this patient? (5 marks)

M04B1 Gluconeogenesis is activated during fasting or starvation giving rise to a low insulin: glucagons ratio. Explain how this activation occurs. Why is gluconeogenesis not the biochemical reversal of glycolysis? How are the irreversible stpes overcome?

M04A4 David Blaine, the famous illusionist survived self-imposed fasting for 44 days in

solitary confinement over the River Thames recently. After weeks of speculation that he was secretly consuming vitamin and glucose supplements in his only source of intake, water, doctors reported on Day 25 that results of his urine tests showed that the sodium chloride levels to be 10 times lower than normal and that the ketone levels were extremely high. Explain why the doctors concluded that he was genuinely starving.

M00B 1 What are the major fuel stores in the body? Describe how they are utilizedduring(a) vigorous short-term exercise such as a sprint,(b) sustained exercise such as a marathon race,(c) starvation

M91A11 Explain briefly how obesity could give rise to hyperglycaemia.

M89A12 Briefly describe how liver phosphofructokinase is regulated and comment on its

significance in the maintenance of blood glucose level by the liver.

M91A11 Explain briefly how obesity can cause hyperglycaemia.

13. DIABETES MELLITUS

Mar06B1 Obesity is becoming a serious health problem worldwide.(a) What is a commonly used index of obesity? ( 4marks)(b) Why are obese individuals more prone to type 2 diabetes mellitus? (6

marks)(c) Identity 2 drugs that have been approved by the Food and Drug

Administration of USA for the treatment of obesity. ( 2 marks)(d) What are the modes of action of the drugs named in (c)? (4 marks)(e) Describe leptin and its physiological effects. ( 4 marks)(f) Briefly outline the signalling pathway of leptin. ( 6 marks)(g) Can leptin be used for the treatment of obesity? Explain your answer.

( 4 marks)

Mar06A5 Explain why the breath of an untreated diabetic smells of acetone.

M05QB4 Your 50 year old uncle recently discovered that he suffers from type 2 diabetes mellitus. He is grossly obese and has a sedentary lifestyle. His doctor prescribed a sulfonylurea drug as well as a thiazolidinedione-type of drug (TZD) and advised him to exercise and reduce his weight.

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a. List the main risk factors of type 2 diabetes mellitus? (3m)b. Briefly outline the progression of the disease. (6m)c. List the causes of hyperglycemia (3m)d. List 4 main differences between type 1 and 2 diabetes mellitus (4m)e. How would exercise help his condition? (1m)f. Explain the molecular basis of the beneficial effects of a reduction on

obesity? (3m)g. Explain how a rise in blood glucose leads to insulin secretion (4m)h. What are the modes of action of sulfonylurea and TZD drugs? (6m)

M02B2 Alex, a 48 year old managing director of a shipping company, was diagnosed with type 2 diabetes mellitus. He is grossly overweight and has a sedentary lifestyle. His physician prescribed sulphonylurea drugs and advised him to lose weight and do moderate exercise. a. Outline the stages in the development of type 2 diabetes mellitus and

compare them with those of type 1 diabetes mellitus. (10 marks) b. Explain how diabetes mellitus may be diagnosed. (3 marks) c. Explain the molecular basis for the use of sulphonylurea drugs in the

treatment of type 2 diabetes mellitus. (9 marks) d. Why are sulphonylurea drugs not used for the treatment of type 1

diabetes mellitus? (2 marks) e. What is HbA1c? (2 marks) f. What is the purpose of the measurement of plasma HbA1c in the

management of type 2 diabetes mellitus? (2 marks) g. Why did Alex’s physician advise him to lose weight? (2 marks)

M01B2 Describe the metabolic conditions that will prevail in an untreated patient suffering from insulin-dependent diabetes mellitus (IDDM), also known as Type I diabetes mellitus.

M01A9 Explain the mode of action of sulphonylurea drugs prescribed for the treatment of Type II diabetes mellitus (non-insulin dependent diabetes mellitus).

A98B1b Describe the biochemical differences between insulin-dependent andnon-insuline-dependent diabetes mellitus.

A97B 1 Describe the alterations in metabolism in an individual suffering from insulin dependent diabetes mellitus who often neglects his medication.

J92A15 Explain the biochemical basis for hyperglycaemia and hypertriglyceridaemia in insulin dependent diabetes mellitus (IDDM)

14. CELL REGULATION / SIGNALLING

Mar08A14 William suffered from an inability in concentrating his urine and was diagnosed with diabetes insipidus. His physician prescribe a nasal spray which appeared to alleviate his symptoms.(a) What is the drug in the nasal spray? (6M)(b)Outline the signalling pathway of this drug. (6m)

May06A13 Outline the signalling pathway by which insulin stimulates import of glucose into cells. ( 8 marks)

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Explain why this physiological response is very rapid. ( 2 marks)

May06B4 With reference to the effect of glucagon on glycogenolysis in liver cells,(a) outline the glucagon intracellular signaling pathway ( 14 marks)(b) identify the steps in this signalling pathway that exhibit signal

amplification. ( 8 marks)(c) describe the processes of receptor desensitization when the receptor is

exposed to high levels of glucagon. ( 8 marks)

M05Q14 a)outline the signalling pathway by which acetylcholine acting onendothelial cells induces vasodilation.(5marks)b)Explain the mode of action of sildenafil citrate (viagra) (2marks)c) Explain the molecular basis if the side-effects of sildenafil citrate.(3

marks)

May05Q11 Explain what is meant by:a) a high potency agonist (3marks)b) a partial agonist (3marks)c) spare receptors (4 marks)

May05Q12 Explain the molecular basis for severe diarrhoea experienced by individuals infected with vibrio cholerae

M04B4 An increase in the intake of salt induces the pituitary to secrete vasopressin. Vasopressin acts via its V2 receptors to increase water retention.(a) Outline the cell signalling pathway which leads to the physiological

response in the kidney. (15 marks)(b) Is this a fast or slow response? How do you account for the speed of

the response ? ( 5marks)(c) What would be the effect on an individual who inherit a mutation

which resulted in the production of inactive vasopressin. How can such patients be treated ? ( 6 marks)

(d) What would be the effect of an inactivating mutation in the gene encoding the V2 vasopressin receptor? Can such patients be treated in the same way as patients in (c) ? Explain your answer. ( 4 marks )

M03A7 Cyclic AMP phosphodiesterase is the enzyme that degrades cyclic AMP to 5’AMP. Methylxanthine inhibits cyclic AMP phosphodiesterase. Explain the effect(s) of methylxanthine on fuel metabolism.

M03A15 Explain why the activation of certain G-protein-linked receptors may lead to increase in cystolic calcium whereas activation of other G-protein-linked receptors may lead to an increase in cyclic AMP with no effect on cytosolic calcium concentration.

M03B3 Describe how the activity of an enzyme can be regulated in a living cell.

A03A11 Outline the intracellular signalling pathway of growth hormone.

J02A12 Explain how steroidal drugs suppress inflammation

M02A13 A patient who was suffering from inflammation resorted to self-medication with aspirin. The aspirin was effective in eliminating the

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inflammation but induced gastric bleeding and gastric ulcers after prolonged use. Explain the molecular basis of these effects.

M01A13 Explain (a) protein phosphorylation, and (b) allosteric modulation. Give an example of each.

M01B1 G-protein linked receptors are members of the largest class of cell surface receptors. They mediate the effects of a large variety of extracellular signaling molecules.

a) With the aid of a simple diagram illustrate the general structural features of members of this class of receptors.

b) Describe the main events of the trimeric G-protein cycle.c) List the molecular targets of each of the following subunits of G-proteins:

γs subunitγq subunitγi subunit

d) Describe briefly how the following intracellular signals are inactivated:(i) cyclic AMP(ii) cytoplasmic free calcium

e) Predict and explain the consequences of inactivation of the GTPase activity of the αs subunit of the G-protein.

M00B3 Describe the regulation of mammalian cell cycle.

M00A9 A certain hormone has two types of G-protein-linker receptors, V1 and V2.Binding the hormone to V1 receptor results in an increase in cytosolic

free calcium while binding of the hormone to its V2 receptor results in an increase in cyclic AMP. Outline the signalling pathways that mediate these responses.

J99A13 Outline the signalling pathway by which prolactin stimulates gene expression.

J99A14 How are cyclin-dependent protein kinases regulated?

A99B3 G-protein- linked receptors form the largest family of cell-surface receptors. Discuss the intracellular signalling pathways which are initiated by the

inactivation of these receptors. Give suitable examples to illustrate your answer.

J98A15 Explain how mammalian cells maintain very low cytosolic free calcium levels.

A98A14 a) Addition of hormone X to responsive cells resulted in a decrease inintracellular levels of cyclic AMP but had no effect on intracellular free

calcium levels. What is the likely explanation for this response?b) Addition of hormone Y to responsive cells resulted in an increase in

intracellular free calcium levels but had no effect on intracellular cyclic AMP levels. What is the likely explanation for this response?

A98A15 How are cyclin-dependent protein kinases regulated?

J96A 11 Explain the biochemical defect that gives rise to diarrhoea in patients infected with Vibrio cholera.

M96A10 Explain how binding of acetylcholine to its receptors on endothelial cells results inrelaxation of smooth muscles of blood vessels.

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J92A14 Explain how cyclic AMP activates cyclic AMP-dependent protein kinase. How is cyclic AMP degraded?M92A15 How would one experimentally identify the enzyme(s) of a metabolic

pathway?

M90A12 Explain by means of a diagram how "calcium mobilising hormone" evokes a

physiological response.

15. BIOLOGICAL OXIDATION

Mar08A4 (a) How is the proton motive force generated in mitochondia? (5M)(b) What are uncoupling proteins and how do they affect the pmf? (5M)

Mar07B2 (a) Show the flow of electrons in the respiratory chain of mitochondria by means of a diagram ONLY. (10M)(b) In the form of a table, enumerate and state specifically the functions of the coenzymes and prosthetic groups involved in the respiratory chain. (10M)(c) What is the possible basis for the use of the following in treating mitochondrial diseases? Explain your answers.(i) Coenzyme Q (5M)(ii) Riboflavin (5M)

Mar07A7 The body of a comatose technologist was hot to touch when found in her laboratory. She was working on metabolic inhibitors of mitochondrial functions. Suggest a likely type of inhibitor that may produce this effect and explain its mode of action.

May06A4 Describe the roles of cytochromes in mitochondrial electron transport. Illustrate by means of a diagram their sites of action relative to the other electron carriers.

M05Q2 The figure below shows the release of hydrogen peroxide by mitochondria isolated from rat liver.

a) What are the respiratory substrates used in the experiment? (2 marks)b)How are these substrates metabolised in the mitochondria? (4 marks)c)Explain the action of rotenone on hydrogen peroxide production. (4 marks)

May05Q5 a) What is the basis of using blue light for the treatment of neonatal jaundice? (4marks)b) Explain how this form of phototherapy can improve the condition. (6 marks)

M04B2 How are reactive oxygen species produced in the mitochondrion?Explain how oxidative stress in the mitochondria can possibly lead to

Alzheimer’s disease (AD).

Table 1: Enzyme activities (expressed in nmol/min/mg protein) of the mitochondrial respiratory complexes of a control and Alzheimer’s disease

subject. Enzyme

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activities (nmol/min/mg protein)NADH dehydrogenase AD 0.040±0.007

Control 0.034±0.004

Succinate cytochrome c reductase AD 0.164±0.023 Control 0.225±0.019

Cytochrome oxidase AD 0.600±0.048*

Control 0.795±0.053

*significantly different compared to Control N ( number of samples ) =15 AD = Alzheimer’s disease

(a) From the date in Table 1, which respiratory complex is affected in Alzheimer’s

disease? Explain your answer . (5 marks)

(b) What is the function of this respiratory complex? (10 marks)

M04A10 How is proton motive force ( pmf) generated in the mitochondrion? ( 5 marks) Explain the action of uncouplers on pmf. ( 5 marks)

A03A9 (a) Name two reactive oxygen species (ROS) (2 marks)(b) How is hydrogen peroxide (H2O2) produced in the mitochondrion? (2 marks)(c) What is the site of action of antimycin in the mitochondrial electron transport chain? (2 marks)(d) From the figure below obtained using a mitochondrial preparation, explain briefly if antimycin produces an oxidative stress. (4 marks)

M01A13 Explain (a) protein phosphorylation, and (b) allosteric modulation. Give an example of each.

M01A3 Compare and contrast the type and relative degree of inhibition of mitochondrial electron transport by:(a)carbon monoxide(b)malonic acid

M01B2 The following refers to mitochondria:(a)Briefly describe how oxidation and phosphorylation are coupled in the mitochondrion.(b)Oxidative phosphorylation is inhibited by oligomycin and cyanide, with pyruvate or succinate as substrate. Explain how you can use dinitrophenol to distinguish between these two inhibitors.

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(c)Rank the following coenzymes or prosthetic group of the mitochondrial electron transport chain in order of increasing electron affinity: cytochrome a; cytochrome b; cytochrome c, CoQ and FAD.

M00B2 Discuss the contributions of the mitochondria to cellular metabolism.

M00A4 The phenolic compound 2,4-dinitrophenol is an uncoupler of the mitochondrial oxidation phosphorylation but the phenolic amino acid tyrosine is not. Explain the difference.

J99A4 Explain why iron is essential for the operation of the mitochondrial electron transport chain.

A99A4 Human liver mitochondria are isolated and placed in a buffer containing succinate. How would you expect (i) the rate of oxygen uptake, and (ii) the size of the

proton motive force to be affected by:(a) addition of a large excess of ADP(b) addition of rotenone, an inhibitor of complex I(c) addition of the contents of a human gall bladder?

J98B3 Describe oxidative phosphorylation in mitochondria. Explain how substances derived from carbohydrates, lipids and proteins are finally oxidised by a common pathway in mitochondria.

A98A7 Paul Boyer was one of the recipients of the 1997 Nobel Prize for chemistry for his contribution to the elucidation of the mechanism of action of ATP synthase. Describe the function of this enzyme complex and its relationship to the other respiratory complexes.

J97A4 Recently a company advertised a health food containing succinate which itclaimed was an excellent source of energy during anaerobic exercise

because succinate could be metabolised directly without oxygen. Do you see anything wrong with this claim? Explain.

J97A6 Menkes disease is a disorder characterized by neuronal degeneration. It is due to

defective intestinal absorption of copper and a decrease in intracellular copper. Explain how this can bring about neuronal degeneration.

A97A5 Antibodies against cardiac ATP-ADP translocase were found in an individual who died from viral cardiomyopathy. How could these antibodies result in death?

J96A9 Ethyl alcohol is completely oxidised in the body and yields usable energy in the process. How much energy (computed as moles ATP synthesized) would you expect from one mole of ethyl alcohol?J96A4 Describe the function of 2 different types of iron-containing proteins in

mitochondrial electron transport. For each, show its position in the respiratory chains.

M96A9 Why would you predict that nicotinamide deficiency might lead to a serious disease?

M96A4 In the electron transport system of the mitochondria, electrons can betransferred ashydride ions, hydrogen atoms or electrons. Give an example

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of each of the above modes of transfer and name the reduced and oxidised forms of the electron carriers.

M95A5 Methylene blue is a dye which can be reduced by several dehydrogenases and the

electron carriers of complexes 1 and 11 of the mitochondrial respiratory system. The reduced form of methylene blue is rapidly re-oxidised by oxygen without the need for an enzyme or catalyst. Explain why injection of methylene blue would (a) decrease the energy (ATP) available from oxidation under normal circumstances but (b) is used as an antidote to cyanide poisoning.

M94A6 Explain a) why mitichondrial oxidation of substrates such as succinate or malate is normally slow in the absence of ADP.

b) how uncouplers, such as 2,4 dinitrophenol, stimulate mitochondrial oxidation in the absence of ADP.

J93A8 What is substrate level phosphorylation? Illustrate your answer with 2 examples.

M93A9 Describe the mode and site of action of the following in relation to metabolism in the mitochondria : a) 2,4 donitrophenol b) oligomycin c) thermogenin.M93A10 Given that the redox potential of cytochrome c is 0.24 volts and that of

cytochrome a3 is 0.39 volts, how many molecules of ATP are likely to besynthesized when a pair of electrons is transferred between the 2 carriers?

J92A7 Explain : a) why mitochondrial oxidation of substrates such as succinate ormalate is normally slow in the absence of ADP.b) how uncouplers such as 2,4 dinitriphenol stimulate mitochondrial

oxidation in the absence of ADP.

M91A7 Describe the participation of iron-sulphur proteins in mitochondrial oxidation of

substrates. Illustrate your answer by means of a diagram to show their sites of action.

M90A7 Draw a diagram of the mitochondrial electron transport chain showing the main

components and the route of electron transfer from NADH to 0.

16. DETOXICATION

Mar08A5 The metabolism of bilirubin involves (a) its conjugation with glucuronic acid and (b) the transport of its glucuronic conjugate. Name two different conditions related to a defet in each of these processes and show the biochemical reactions involved.

Mar08A7 John was quite healthy until he received prescription for chloroquine, an anti-malarial druf, in preparation for a trip to Cambodia. Just prior to his departure for Cambodia, he complained of weaknes and noted that his urine had recently become unexplainably dark. Physical examination revealed slightly jaundiced sclera. What could be the cause of John’s condition. Explain the molecular events that induced the jaundice.

Mar07A10

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diclofenac

(a) Diclofenac is a non-steriodal anti-inflammatory druf (NSAID). Provide two

possible routes of its detoxification and elimination. (6M)(b) If phenobarbital, an inducer of glucuronyl transferase is co-

administered, how would the pattern of the excretory products of diclofenac be

affected? Explain your answer. (4M)

Mar07A8 Give 2 examples of how the human body deals with excess ammonia generated during metabolism?

May06A12 The metabolism of bilirubin involves the conjugation and transport of its conjugated metabolites. Describe the biochemical reactions involved and name a clinical condition associated with a defect in each of these steps of metabolism.

M05Q11 isoproterenol is a catecholamine which was once used for the treatment of asthma. Its structure is shown below. Explain two modes of its biotransformation and excretion from the body, illustrating your answers with biochemical reactions.

May05pBQ1Besides urea synthesis and excretion, Show clearly how ammonia generated during metabolism may be removed from the human body. (30 marks)

May05Q14 Explain the importance of heme proteins in mitochondrial electron transport. Illustrate your answer by means of a diagram to show their specific names and sites of location.

May04A7 a. What is the cause of neonatal jaundice? (4marks)b. How is this condition normally treated in clinics (3 marks)c. Explain the basis of this mode of therapy (3 marks)

M04A11 Explain the importance of cytochrome P450 in drug metabolism. ( 6 marks) By means of an example, explain how the action of cytochrome P450 may results in a more toxic intermediate. (4 marks)

A03A10 The following results were obtained from the laboratory investigation on the serum of a patient___________________________________________________________ Patient’s result Normal range

(umol/L) (umol/L)Serum bilirubin (Total) 90 5-30

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Serum bilirubin (conjugated) 5 0-5Serum bilirubin (unconjiugated) 85 5-25___________________________________________________________What is the likely clinical condition of this patient? Explain your answer.

A03B2 (a) List three different types of phase I reactions and explain why they are important in the detoxification process. (10 marks)(b) List the components of the cytochrome P450 electron transport system. What is the role of each component? (10 marks)(c) Malathion is a common insecticide. Suggest one phase I reaction for the detoxification of this molecule. By means of arrow/s, show on the structure provided below, the possible site/s of its biotransformation (10 marks)(next page)

S OCH3 O P S CH C O CH2CH3CH3 O O

CH2 C O CH2CH3

Malathion

M03A5 Name three different conjugating agents required for the detoxification of xenobiotics which possess phenolic groups. For each, illustrate its participation in a phase II (conjugating) reaction.

J02B1 How does the human body cope with its metabolically-generated ammonia?

J02A9 α-Methyldopa, whose structure is shown below, is an antihypertensive drug. Suggest three ways by which it may be biotransformed and excreted.

α-Methyldopa

M02A6 Describe two detoxification reactions by which sodium benzoate, a common preservative, may be metabolized and excreted.

M02A5 What would be the likely cause of an increase in serum bilirubin glucuronide?

Explain your answer.

M01A4 The most common pain killer prescribed after a tooth extraction is acetaminophen (known locally by its trade name as paracetamol). Explain how this analgenic is detoxified by the human body. How are patients with an overdose of paracetamol normally treated? Explain the rationale of this therapy.

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M01A11 By means of four different examples, illustrate the energy-requiring processes in Phase II or conjugate reactions involved in the detoxification of xenobiotics.

M00A8 Explain the rationale of phototherapy in treatment of neonatal jaundice.

J99A7 (a) Describe the transport and conjugation of bilirubin.(b) How is the biosynthesis of heme normally regulated in the body.

J98A5 Explain why cytochrome P450 is important in the detoxification of xenobiotics. Illustrate your answer with two examples.

A98A6 Give the enzymic reaction and its importance in each of the following aspects of haem metabolism:

a) the insertion of iron to form haemb) the regulation of haem biosynthesisc) the degradation of haem to bilirubin

A97A6 What is the cause of neonatal jaundice? Explain the basis of blue lightphototherapy of this condition.In a recent clinical trial, it was proposed that light from a blue-green

fluorescent lamp was more effective than bluelight in the treatment of neonatalhyperbilirubinaemia. From the table below (which shows average values),

do you agree? Explain your answer.

A97A7 It is sometimes stated in older textbooks that ethyl alcohol in beverages isdangerous for diabetics because the liver can convert it to intermediates

which in turn raise blood sugar.Is this a reasonable statement? Explain your answer.

J96A7 For each of the Phase 1, 11 and 111 reactions in detoxification, give an example and the biochemical reactions involved.

J96A2 Explain how biliary obstruction could impair blood coagulation.

M96A8 By means of a three different examples, explain how glutathione can participate in the detoxification of hepatoxins and carcinogens.

M95A7 Describe the detoxification reactions involved in the metabolism of paracetamol (or acetaminophen).

J94A7 Explain the biochemical basis of porphyria. Illustrate your answer with two examples of the clinical condition in which different metabolites of porphyrin can accumulate.

17. NUTRITION

Mar08A13 Explain the functions of vitamin B12. (6m)Explain why injections of vitamin B12 cured her condition but intake of tablets of vitamin of B12 could not. (4M)

May06A14 What are the functions of the following water-soluble vitamins?(a) vitamin B1 ( thiamine) (2 marks)(b) Vit B2 (riboflavin) (2 marks)

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(c) Biotin (2 marks)(d) Niacin (2 marks)(e) Folic acid (2 marks)

Mar06A10. With reference to Vit D(a) outline the pathway for the biosynthesis of 1,25

dihydroxycholecalciferol. ( 3 marks)(b) outline the signaling pathway by which 1,25 dihydroxylcholecalciferol

induces cellular responses. ( 3 marks)(c) what is the effect of a deficiency of Vit D? ( 2 marks)(d) what is the effect of consumption of excessive amounts of vitamin D

over an extended period of time? ( 2 marks)

M05Q15 a)List 5 beneficial effects of vitamin A (5 marks)b)What are the harmful effects of an excessive intake if vitamin A? (5 marks)

May 05Q13 What are the functions ofa) riboflavin (3marks)b) niacin ( 3 marks)c)vitamin B6 (4 marks)

May04B1 Describe the functions of Vitamin A and Vitamin K.

M03A4 What role(s) does each of the following play in metabolism?(a) vitamin B6(b) biotin

M02A14 A deficiency in vitamin C can give rise to a number of ill effects. What are these ill effects? List the functions of vitamin C in humans.

M01B3 From your knowledge of biochemistry, explain why a deficiency in the diet of each of the following is likely to give rise to a serious disease:(a)Riboflavin(b)Ascorbic acid(c)Thiamine(d)Iron

J99A9 An advertisement for a slimming salon states that "starchy foods make you fat". Explain this statement in metabolic/molecular terms.

J99A11 You ask for $ 10,000 for a research project involving depleting subjects ofvitamin C and measuring the effect of this on wound healing. The grantingauthority offers the fund on condition that the trial is conducted on rats,

not humans. What is your response to this? If allowed to go ahead with the use of humans, how would you make the diet poor in vitamin C?

A99A7 A patient comes to you for a tooth extraction and you noticed that he hasswollen extremities. He says that he is nauseated by food and can only eat

white bread. What condition might he be suffering from and what enzyme(s) in his red blood cells could be assayed to confirm your suspicions?

J98A8 Why might you predict that the lack of thiamine in the diet will result in aserious disease?

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J98B2 "Metabolically, obesity and starvation are two sides of the same coin."Critically discuss this statement.

A98A11 What is thought to be the role of leptin in the modulation of body composition?

A97A8 Rats are allowed to develop full-blown vitamin A deficiency through manipulation of the diet. They are divided into four groups, and each group is given either ß-carotene, retinol. retinal, or retinoic acid. Describe the physical condition of the rats before this administration and the possible states of the various groups thereafter.

M96A11 Explain why a severe dietary deficiency of ascorbic acid often leads to numerous skin lesions and bruises on arms and legs.

J95A6 Advance plausible reasons why (a) alanine is occasionally administered to subjects

recovering from starvation who nevertheless malabsorption, (b) oedema often occurs in severe starvation and C alcohol is sometimes given as an emergency nutrient.

J94A8 Outline the importance of P-carotene in human nutrition.

M94A8 Explain how a deficiency of thiamine in the diet will produce serious effects on health.

M94A14 Explain why it is not advisable to have an excessive intake of vitamin A and D though they are needed for the development of healthy calcified tissues.

J93A10 Why is it difficult to determine the exact dietary requirement for a specificnutrient?

M93A1 1 Discuss the followinga) Protein quality b) essential fatty acids c) vitamin B complex

J92A1 1 Show, in chemical terms, how vitamin C may be inactivated by heat.

M92A12 What is the connection between vitamin A and disturbances of vision?

M91A13 What is a) dietary fibre b) the set point theory of obesity c) the basis of energy provision by ethanol.

M90A14 What do you understand by the term, vitamin? Name the vitamin which form a precursor for the prosthetic group in a) succinate dehydrogenase b) an enzyme involved in carboxylation reaction.

18. CONNECTIVE TISSUE

May06B2 Discuss how the structures of globular and fibrous proteins are well-suited for their biological functions. For each type of protein, illustrate your answer with a suitable example.

Mar06A2 What is the sequence motif of the triple helix of collagen? How does the triple helix contribute to the stability of collagen?

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M05Q13 You are taking a new sport activity: waterskiing. This means your long bones (especially those of your legs) have to undergo remodelling as a response to new loads and stress-strain topographies. Which cell types and which enzymes will be involved?

May04A14 Explain the differences in the structures and functions of type I and type IV collagens.

M04A14 Briefly describe (a) the general structure of glycosaminogylcans (GAG) (4

marks)(b) the functions of GAGs in connective tissues (6

marks)

M03A14 Explain why the absence of a protease that cleaves the pro-peptide sequence of fibrillar collagen (type , II & III) results in Ehler Danlos syndrome. Individuals afflicted with this syndrome exhibit hyper-extensible skin, easily dislocated joints and capillary bleeding.

A03A8 What are the structural features of glycosaminoglycans? Explain how these structural features strengthen connective tissues.

J02B3 Describe the structure, biosynthesis and function of type 1 collagen.

M02A15 Patients suffering from Ehler-Danlos syndrome Type VII inherit an inactivating mutation in a gene that encodes a protease. The skin of such patients bruises easily and they are liable to suffer from dislocation of major joints such as those of the hips. Explain the molecular basis of these symptoms.

J99A12 In separate experiments, proline and hydroxyproline individually laballed with 14 C are added to the diet of an animal. Which of the amino acids, if any, will be labelled in the animal's collagen? Explain your answer.

A99A13 What are the main constituents of proteoglycans? Using an example, explain briefly the structure and function of this class of macromolecules.

J98A1 1 What are glycosaminoglycans? Give an example and explain how it functions in the tissues in which it is located.

J98BI Give a detailed account of the structure, biosynthesis and assembly of thecollagen.

A98A10 Name 2 types of collagen diseases and explain their underlying biochemical defects.

N97A 11 Describe the functions of fibronectin in connective tissues.

A97B3 Describe the process of collagen synthesis, assembly and maturation.

J96A15 As bone and teeth age, the number of cross linkages between tropocollagen increase. How does this affect these tissues?

J96A10 Describe the interactions between cells and fibronectin.

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M96A14 Give the structure of a typical glycosaminoglycan tissue. How does its structure relate to any of its biological functions in such tissues?

J95A10 The seeds of the sweet pea, Lathyrus odoratus, containing aminopropionitrile,NC.CH2.CH2.NH3+, which is an inhibitor of lysyl oxidase. Explain why animals ingesting these seeds are often found to have extremely fragile collagen.

M95A1 1 Cosmetics and foods containing 'supercollagen' have been put on sale recently. It is claimed that the application of such cosmetics to the skin and intake of such food prevents wrinkles and gives a smoother skin. Is there any biochemical basis for these claims? Give the reasons for your answer.

J94A 12 Describe the formation of one type of covalent cross-linkage in collagen fibres. As we grow older, the number of these cross linkages increases. How does this change affect tendons?

M94A12 The helical polypeptide chains of the tropocollagen molecule consist of thesequence (Gly-X-Y)n where X and Y represent other amino acids and Y isfrequently hydroxyproline.Explain the significance of the following features of the structure of

collagen.(a) That every third residue is glycine(b) The frequent occurrence of hydroxyproline in the chains.

J93A13 Describe the formation of one of the cross-linkages in collagen.

J92A12 Draw a diagram of fibronectin and indicate clearly its functional domains.M91A14 Describe the arrangement of Type I collagen that occurs in bone.

19. MINERALS

Mar06A6 Briefly explain how a deficiency in alkaline phosphatase affects development of teeth and bones.

M05QB1 Describe the calcification of bone. Your answer should include the names of the cellular, organic, and non organic partners involved. How is bone calcification different from dental calcification?

May05Q7 Hypophosphatasia is a monogenic oral disorder.a)briefly explain the cause and symptomps of this disease (6marks)b)Is it possible to correct this defect and if so, how can it be performed?(4 marks)

M04A13 What are the biochemical functions of (a) riboflavin (4 marks) (b) biotin (3 marks) (c) niacin (3 marks)

J02A13 Explain the difference between marasmus and kwashiorkor.

J02A8 Discuss how environmental lead can induce anemia.

M02A12 What would be the effects on bones and teeth of maintaining the following fluoride levels in our drinking water? a. 1 ppm (4 marks) b. 4 ppm (3 marks) c. 25 ppm (3 marks)

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(ppm = parts per million)

A99A 11 What is the mechanism of action of sildenafil citrate (Viagra) taken by patients suffering from impotence? Explain why its use by patients who are also taking organic nitrates is contraindicated. Explain why its use may also cause temporary vision loss in some patients.

A98B3 Write an essay on the calcification process in bone and dentine.

J95A14 Describe how zinc may affect acid-base balance in the body.

J95A15 How does parathyroid hormone affect the metabolism of calcified tissue?

J95B3 Give an account of the current understanding of the process of calcification 4.Describe any two forms of non-haem iron-protein complexes and their roles in iron metabolism.

M95A15 Hydroxyapatite is the main inorganic substance present in calcified tissue. What are its physical and chemical characteristics which make it a suitable material in such tissue?

A95B3 Discuss the metabolic roles of vitamins which are implicated in the capture of energy from oxidisable substrates.

A95B4 How does fluoride inhibit the formation of dental caries?

J94A13 Explain why a dietary deficiency of copper may lead to a premature greying of hair.

J94A14 How do parathyroid hormone and calcitonin affect the metabolism of calcified tissues?

J94B3 Give an account of the present understanding of the process of calcification

J95A14 Describe how zinc may affect acid-base balance in the body

J95A15 How does parathyroid hormone affect the metabolism of calcified tissue?

J95B3 Give an account of the current understanding of the process of calcification 4 Describe any two forms of non-haem iron-protein complexes and their roles in iron metabolism.

M95A15 Hydroxyapatite is the main inorganic substance present in calcified tissue. What are its physical and chemical characteristics which make it a suitable material in such tissue?

A95B3 Discuss the metabolic roles of vitamins which are implicated in the capture of energy from oxidisable substrates.

A95B4 How does fluoride inhibit the formation of dental caries?

J94A13 Explain why a dietary deficiency of copper may lead to a premature greying of hair.

J94A14 How do parathyroid hormone and calcitonin affect the metabolism of calcified tissues?

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J94B3 Give an account of the present understanding of the process of calcification

M94A13 Describe with the aid of a diagram. the intestinal absorption of non-haem iron.

J93A11 Compare the structures. sites of production and effects of hormones involved in calcium homeostasis.

J93A11 How is iron absorbed and transported in the body?

M93A12 Outline how 7-dehydrogenase ( provitamin D3 ) is converted to its active form. Explain briefly the mechanism by which the active form of the molecule

increases plasma calcium level.

J92A10 What are the common causes of iron overloaded?

M92A10 Outline the pathway for the biosynthesis of thyroxine (T4) and 3,5,3thiodothronine (T3).

M91A12 Describe the proteins involved in a) storage b) transport of iron in the body. Explain how the structures and properties of these proteins are suited to their respective functions.

M90A13 Thyroid hormones are stored in the colloid of the thyroid gland follicles. How are these thyroid hormones released into the circulation?

20. CANCER

M00A10 Describe three common types of drug resistance observed among cancerpatients.

J99B4 Write an essay on the molecular basis of cancer.

A99A12 What are the genes which are deleted or inactivated in patients with (a) Familial

Adenomatous Polyposis and (b) Hereditary Nonpolyposis Colorectal Cancer which

predispose them to high rates of colorectal cancer? Briefly describe thefunctions of the proteins encoded by these genes.

A99B4 What is meant by the term "mutation of DNA"? Briefly explain how mutations can occur and be corrected in human DNA. Describe two methods that can be used to detect mutations in the human genome.

J98B4 Write an essay on oncogenes.

A98B1 a)Describe how a defect in cell signalling leads to human disease.

A97A14 What evidence supports the multi-hit hypothesis of tumourigenesis?

J96A12 Mutations in the Ras gene are very common in human cancer. Explain the nature of the mutations that convert the Ras proto-oncogene to an oncogene. How does these mutations affect the function of the Ras protein?

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M96A12 What capabilities, beside regulated cell proliferation, must cancer cells possess to enable them to metastasize?

M92A13 Describe a biochemical mechanism which results in activation of indirect-acting

carcinogens.

M91A15 Explain how defects in DNA repair mechanisms predispose to occur.

21. DENTAL / ORAL BIOCHEMISTRY

Mar08A11 You are consultant to a public health manager for a pacific island. The local government has implemented in 2003 fluoridation of drinking water to increase dental hygiene and health. A dental screening of the population shows that adults have experience a stablisation of caries and the incidence of cavities. Children born in the last 5years seemed to have developed whitish specks on frontal teeth, whereas children that were born in 1997 and earlier do not show this. What do you think has happened and what kind of changes would you suggest?

Mar08A15 Explain why calcium and phosphate leach out from enamel when the pH is below 5.5.

Mar07B4 The pH of the dental plaque of a person who had not brushed his teeth for 4 days were monitored before and after a 2 minute rinse with 20% glucose. The changes in the dental plaque pH are shown below.

*8 (a) Account for the sharp fall in plaque pH (4M) (b) Account for the subsequent gradual rise in pH. (7M) (c) What would be the pH changes if the experiment were to be repeated after the subject had brushed his teeth? Illustrate your answer with the aid of a diagram. Explain your answer. (4M) (d) At what pH would enamel hydroxy-apatite start to dissolve? (3M) (e) What cause hydroxy-apatite to dissolve below critical pH? (10M) (f) What would happen if instead of a single 2-minute rinse with glucose solution, the subject were to rinse his teeth with the same glucose solution at 10 minute intervals for the next 2 hours? (2M)

Mar07A14 Explain the changes in the pH of the saliva when the secretion by salivary glandsis stimulated.

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May06A15 What was the early hypothesis regarding the mechanism by which fluoride reduces the incidence of dental caries? ( 3 marks)What are the observations that gave rise to doubts about the early hypothesis? ( 3 marks)What is the major mechanism by which 1 ppm of fluoride reduces dental caries? ( 4 marks)

Mar06A9 Describe the calcification of teeth. Your answer should include the names of the cellular, organic and non-organic partners involved. What are the differences of this process compared to bone calcification?

Mar06A13 Briefly describe the anti-bacterial factors in saliva.

Mar06A14 Explain why there is a strong correlation between the cariogenicity of a dental plaque bacterium and its ability to secrete dextran and levan sucrases. ( 4 marks)(a) describe the reaction catalysed by dextran sucrase. ( 4 marks)(b) describe an experimental technique that can be used to demonstrate

conclusively that the ability to secrete dextran sucrase is vital for the production of dental caries by a dental plaque bacterium. ( 2 marks)

M05Q10 Explain why the pH of saliva increases when its flow rate increases.May05Q15 After a glucose rinse, the pH of dental plaque falls rapidly but rises

gradually thereafter. Explain the causes of these pH changes. May04B2 Explain the mechanism by which fluoride reduces the incidence of

dental caries.May04A13 Briefly describe the structure and functions of salivary mucinsM04B3 Write an essay on the current knowledge of the genetic basis of oral

diseases.M04A15 Explain why strains of streptococcal mutans that have lost their ability to

produce extracellular glucans and fructans are not cariogenic.

M03A12 Explain why strains of Streptococcus mutants that do not carry the genes encoding dextran sucrase and levan sucrase are not cariogenic whereas the wild-type strains are extremely cariogenic.

M03A13 List the anti-bacterial proteins in saliva and explain how their activities offer some degree of protection to enamel.

A03A2 Explain the effect of an increase in saliva flow on the pH of saliva.

A03A7 Explain the effects of 2 parts per million fluoride in drinking water on dental health.

A03B3 Describe the formation and maturation of bone and enamel.

J02A14 List the conclusions of the Vipehom study.

J02A15 Describe the structure and function of laminin.

M02B3 Saliva fulfills vital functions. The importance of saliva becomes evident in patients suffering from xerostoma. a. What are the causes of xerostoma? (3 marks) b. What are the symptoms of xerostoma? (3 marks) c. Why are ill-effects experienced by xerostoma patients very severe? (24 marks)

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M01B1 The formation of dental plaque has been linked to the producation of ammonia by the action of the urease of oral bacteria acting on salivary urea. In an effort to decrease plaque formation, several compounds were tested for their inhibitory effects on urease activity. The following kinetic plot was obtained for candidate compound NTPLAK.(a) What type of inhibition does the compound exert on urease activity?

Explain your answer with reference to the kinetic plot.(b) What can be inferred about the structure of the compound?(c) Would you expect urease to exhibit co-operativity? Give reasons.

M01A14 Describe the features of dental fluorosis.Explain the molecular basis of dental fluorosis.

M01B3 Micro pH electrodes were placed in partial dentures of volunteers and the pH of their dental plaques measured and recorded in real time after a glucose rinse (Stephan curves).

(a)By means of a diagram illustrate the Stephan curve of a subject with good oral hygiene and one with poor oral hygiene.

(b)What are the similarities and differences between the two Stephan curves?

(c)Account for the drop in pH of the Stephan curve.(d)Account for the recovery phase of the Stephan curves.(e)Relate the Stephan curves to the prevalence of caries in the subjects.

M01A14 Fluoride in drinking water, at a concentration of one part per million reduces the incidence of caries by about 50%. Explain the mechanisms of action of fluoride that cause this effect.

M01A13 Explain why the cariogenicity of dental plaque bacteria correlates quite well with their ability to produce extracellular polysaccharides.

M01A12 Saliva secretion is stimulated in response to the presence of food. Compare the characteristics of salivary secretion in the unstimulated state with that of the stimulated state with respect to:

(a) PH(b) Concentration of HCO3-

(c) Concentration of mucin Offer explanations for the differences in each case.

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M01A8 Give an example of an oral condition that is inherited. Briefly describe the symptoms and a method to confirm the underlying causes for the cited disease or defect.

M00A15 Briefly explain why a combination of poor dental hygiene and sucrose-rich diet can result in dental caries.

J99A15 Describe the mechanisms responsible for the formation of calculus.

J99B2 Write an account of the calcification process in dentine.

A99A 14 Describe the dental effects and mode of action of fluoride.

A99A15 Describe the mechanisms contributing to the recovery phase of the Stephan curve.

J98A13 Describe briefly the synthesis of extracellular polysaccharides by bacteria in dental plague.

J98A14 List three ways by which fluoride is considered to inhibit caries.

M98A12 Name 3 salivary proteins with antibacterial properties. Describe the biochemical basis for their actions.

A98A13 What is gingival crevicular fluid? Why may it: be of diagnostic interest todentists?

A97A13 The following below shows the titration with acid of a sample of a saliva of a healthy individual. Comment on regions A, B and C of the titration curve. What substances found in saliva might have contributed to the effects shown in

regions A and B?

A97AI5 Explain why a thick viscous dental plague is more likely to lead todemineralization of the enamel composed to one of that is thin and

porous.

J96A13 Which component(s) of saliva are effective in acid-base buffering? Explain why they are effective.

J96A14 Give the reaction catalysed by dextran sucrase. How does the product of this reaction contribute to cariogenesis?

M96A15 Briefly explain why we are convinced that fluoride that has been incorporated into enamel plays only a minor role in the inhibition of caries formation.

J95A12 Give the significance or function in oral biology of the following components of

saliva:(a) fluoride, (b) thiocynate, and (c) biocarbonate.

J95A13 Sketch a typical Stephan curve. Explain the significance of the main features of the curve.

M95A12 Explain why saliva is not an ultrafiltrate of plasma.

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M95A13 What insights into the cause of denial caries can be obtained from experiments on animals?

J94A15 Describe the properties and functions of proline-rich salivary proteins.

M94A15 How does fluoride inhibit acid production by plaque bacteria?

J83A14 Describe the process of salivary fluid secretion by the major salivary glands. In what ways do the secretions of the submandibular and the parotid glands differ?

J93A15 Explain how the dental pellicle is formed. Discuss its role in caries formation.

M93A14 What is the major immunoglobulin in the secretion from the major humansalivary glands? How does it differ from the immunoglobulins of the ~c

class in plasma? Give an account of how it is processed and secreted by the salivary gland cells.

M93A15 Why does denial plaque become thick and gelatinous when a diet which is rich in

sucrose, lactose or maltose is consumed? Identify the most cariogenic of these sugars and explain why it is so. In addition, explain how plaque is formed in the presence of these sugars promotes the formation of carious lesions.

J92A13 The enamel of extracted teeth was incubated with solutions of 0. 1M sodium lactate of varying pH (from pH 2 to pH 8) in vitro. Draw a graph showing the varying amount of calcium that leaches out of enamel as a function of pH- Comment on the significance of the experimental results.

M92A14 Why is saliva anti-cariogenic?

M90A 15 What insights into the causes of dental caries have been obtained withexperiments using germ-free animals?

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1. Blood

Mar06Q1 Briefly discuss how the following conditions would lead to excessive bleeding:(a) reduced platelet count(b) lack of coagulation factor VIII(c) lack of the Vit K(d) excessive heparin infusion

M05Q1 Mrs Lee a, 30 year old who is 6 months pregnant with her first child , consults her doctor because she is suffering from frequent dizziness. The doctor suspects that she is anaemic and may require blood transfusion.a. Define 2 parameters in the peripheral blood that are useful for the

determination of anaemia. (4m)b. Explain the principle underlying the determination of Mrs Lee’s blood

group. (6m)

M04B2 Using the oxyhaemoglobin dissociation curve as illustration, explain how the binding of oxygen to haemoglobin may be affected in the following :

a. Hypoventilation

b. Diabetic ketoacidosis

c. Fall in body temperature

M04C6 The Prothrombin Time (PT) is a test for factors in the extrinsic and common pathways of the coagulation system. The activated Partial Thromboplastin Time (aTTT) is a test for factors in the intrinsic and common pathways of the coagulation system.

a. Explain what happens to these parameters for a person

i. Suffering from haemophilia A (coagulation factor VIII deficiency)

ii. With a platelet count of 40 x 103 per μL (Normal 200 x 103 per μL)

b. Under what conditions would both of these parameters decrease? Explain.

M01B9 Discuss the various mechanisms that (a) localizes blood coagulation to the area of tissue injury and (b) prevent coagulation from spreading to the rest of the vascular system.

M01A2 Concisely explain the basis for the ABO blood grouping system.J99A2 Give a concise account of the basis of ABO and Rh blood grouping.J98B7 Discuss the physiological processes involved in hemostasis.A98A6 Briefly discuss the consequences of mismatched blood transfusion

involving a) ABO and b) the Rh blood group system.J97B7 Give an account of factors which affect fluid exchange at the capillaries.J97A2 Outline the basis of ABO and Rh Blood GroupingA97B8 Discuss the importance of the following factors in hemostasis and blood

coagulation:a)coagulation factor VIIIb)vitamin K

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c)plateletsJ96A3 Outline the roles of the nutritional and hormonal factors essential for

erythropoiesis.M96A2 Discuss concisely the importance of blood groups in blood transfusion.M94A1 Give an account of the factors which affect the rate of erythrocyte production.J93A2 Discuss the role of platelets in hemostasisM93A6 Briefly discuss the function of haemoglobin.M93B7 Outline the basis of A, B, 0 and Rh blood grouping. Discuss the consequences of

transfusing 200ml of group B, Rh -ve blood into a person with group AB, Rh+ve blood.J91B1 Discuss the processes that help to arrest bleeding following an injury.J91A4 Discuss the nutritional factors essential for normal erythropoiesis.M91A6 Briefly describe the processes which prevent blood coagulation within the

normal circulation.

2. Immune System

A03A1 Give the normal differential white blood cell(WBC) count in man. Briefly describe some of the functions of these cells.

J02A6 Briefly discuss the roles of the following cells in immunity: a. macrophages b. B-lymphocytes

A99A4 Briefly discuss the major functions of macrophages in the immune response.A98A3 Give a brief account of the functions of antibodies.J97A3 Discuss briefly the main functions of the immune system.J96B8 Discuss the interactions between macrophages. T-lymphocytes and

B-lymphocytes in the production of an immune response on exposure to an antigen.M96A5 Briefly discuss the role of antibodies in the defence mechanisms of the body.J92A3 What is humoral immune response? Briefly discuss the functions and mechanism of actions antibodies.M92A2 Briefly discuss the role of helper T-lymphocytes (CD4+) in an immune response.M91 A3 Discuss briefly the genetic basis of antibody diversity.M90A 1 Give an account of the origin, function and fate of the alveolar

macrophages.

3. Cell Membrane Physiology

M06Q6 Describe the sequence of events at the neuro-muscular junction and briefly explain how these changes elicit a contractile response in the skeletal muscle.

M05Q5 Keeping in view the physiology of excitation-contraction coupling, briefly explain the mechanism in which neuromuscular blocking poisons affect postsynaptic transmission.

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M04B5 Describe excitation contractoin coupling. What role does intra- and extra- cellular calcium ions play in the excitation of skeletal muscle fibres?

A03A5 Explain the ionic basis for the various phases of the nerve action potential.J02A2 Briefly explain the similarities and differences in the action potentials of

skeletal and cardiac muscles.M02A4 In an experiment to determine the effect of extracellular ionic changes on the

contractile response of skeletal muscles, a frog skeletal muscle preparation is bathed in an isotonic solution and connected to a recording device for measuring muscle contractions. Briefly explain how the following changes will affect the contractile response in this experiment: a. Increasing the concentration of KCl in the bathing solution. b. Adding acetylcholine to the bathing solution. Would the absence of Na+ ions in the bathing solution affect the response to acetylcholine?

M01A6 Briefly describe the various modes of trans-membrane transport.M01B7 Discuss the physiological processes which help maintain the osmolality of body fluids within a narrow range in healthy individuals.M01A5 Write a short account on the Na+/K+ ATPase pump.M00A5 Describe the ionic basis for the various phases of a skeletal muscle action

potential.J99A6 Briefly discuss the role of cyclic AMP and intracellular Ca++ as second

messagers.J98A1 Discuss the various modes of trans-membrane transport.A97A2 Briefly discuss the factors responsible for the resting membrane potential.J96A2 Briefly explain the basis of postsynaptic and presynaptic inhibition.J96A1 Summarize the processes that regulate the absorption of Na+, K+ and

HC03- decrease from the gastrointestinal tract.M96A3 Name the processes by which various substances move across the cell

membranes indicating which of these processes require energy and how isenergy provided. Give appropriate examples to illustrate your answer.

M94A5 Explain the generation and maintenance of the resting membranepotential.

J93A1 Explain how action potentials in the motor neurons at the neuromuscularjunction lead to contraction lead to contraction of the skeletal muscle.

M93A4 Describe the role the sarcoplasmic reticulum and transverse tubules in muscular

contractions.J92A2 Describe, with appropriate diagrams, the action potential of a cardiac

muscle fibre and explain why cardiac muscle cannot be tetanised.

M92A3 Describe the ionic basis of action potentials in a nerve fibre.J91A3 Outline the events that couple excitation to contraction in skeletal musclesM91A2 Compare and contrast the process of impulse transmission in a myelinated

nerve fibre.M90A4 Discuss the effect of resting membrane potential of a nerve fibre when the

concentration of potassium in the extracellular fluid is increased a) minimally, and b) by a large quantity.

4. Cardiovascular System

M06Q3 A healthy adult male had lost significant amounts of body water through hours of perspiration and with inadequate intake of water to replace the loss.

(a) Explain how cardiac output maybe affected in this individual. ( 5 marks)

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(b) Explain how the renin – angiotensin system may be affected in this individual. ( 5 marks)

M06Q7 Mr Lim is a patient with chronic heart failure, treated with the loop diuretic furosemide, which inhibits sodium reabsorption at the thick ascending limb. He now required an operation for removal of a tumour in his jaw. During his preoperative workup, his dental surgeon and anesthetist find that he has minimal edema in his lower limbs, but his serum potassium is low.(a) explain how the use of furosemide helped to reduce edema in Mr Lim.

( 10 marks)(b) Explain how Mr Lim’s low serum potassium might have arisen. ( 10

marks)

M05Q4 Miss Lim, a 55 kg lady, lost 750 ml of blood in an accident and is found to be hypotensive.a. Explain how interstitial fluid shifts into the intravascular space in this

situation. (2m)b. Describe briefly the other physiological responses that together restore

intravascular and ECF volume to the normal. (8m)

M04B3 An adult male was seen at the Emergency Department for acute left ventricular failure. His pulse rate was 130/min. His arterial blood pressure was 80/30 mmHg.

a. Explain how this individual’s cardiac output may be affected b. Explain the observed blood pressure recording.

A03B8 A 56 year old female adult was found to have congestive heart failure.(a) Explain how her arterial blood pressure may be affected.(b) Explain how the activity of her cardiac sympathetic nerves may be

affected.(c) Fluid retention may occur in this patient. Explain the effect of fluid

retention on transcapillary fluid filtration.J02B8 An adult asthmatic patient was noted to be extremely breathless and his

arterial partial pressure of oxygen (PaO2) was 74 mmHg (normal 100 mmHg) a. Describe how oxygen is transported in blood. b. In asthma the main pulmonary pathology is obstruction of airways.

Explain how this PaO2 can come about. c. How does this reduced PaO2 affect the transport of oxygen and the

oxygen content of blood?M02B7 An individual was brought to the hospital after sustaining injuries at a road

traffic accident. There was no external evidence of bleeding. The doctor suspected that there might be internal bleeding as the patient appeared pale, his pulse rate was rapid and systemic blood pressure was 86/60 mmHg. a. Explain how blood loss may lead to the patient’s presenting blood

pressure. b. Explain the mechanisms leading to an increase in pulse rate. c. Explain how delivery of oxygen to the tissues may be affected.

M02A3 Explain why the plasma sodium concentraton sometimes becomes abnormally low in patients with congestive heart failure.

M01B7 A sudden significant loss of blood from the body results in vasoconstriction to maintain blood pressure.a. Explain how this occurs and how it helps maintain blood flow to the heart and brain.

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b. Explain why blood flow to the skin and gastrointestinal tract may decrease under these circumstances.

M01A3 Briefly explain how hypoxia may occur in a person with left ventricular failure.M00A2 Define cardiovascular shock. List and explain the physiological causes of

cardiovascular shock.J99B7 Discuss the regulation of cardiac output and venous return during exercise.A99A6 Explain the following: Starling's law of the heart, cardiac contractility, total

peripheral resistance, Korotkoff sounds.J98B8 Define "circulatory shock". How does hypovolemia give rise to circulatory shock?

Discuss how the body compensate in circulatory shock.A98A4 With the aid of a graph, show how cardiac output changes as heart rate

increases. Explain your answer.J96B7 Discuss the compensatory mechanisms that operate to maintain normal blood pressure.M96B8 Discuss in detail the regulation of blood flow to tissues.M94B7 Discuss the roles of the following in the regulation of arterial blood pressure:

(a) Kidneys(b) Baroreceptors

M93A2 Discuss the factors involved in the regulation of cardiac output.J92B2 Describe the short term and long term mechanisms that help to regulate

systemic arterial blood pressure following haemorrhage.M92A6 Describe the mechanisms by which pulmonary edema may develop as

consequence of left ventricular failure.J91 B2 What is the normal pacemaker of the heart? Discuss the factors regulating

heart rate.M91A1 Discuss the role arterioles in the distribution of blood flow to different

organs of the body.

5. Respiratory Physiology

M06Q4 An adult patient was noted to have respiratory depression after general anaesthesia. Central cyanosis was present in this patient.

(a) Explain how this may affect this patient’s arterial partial pressure of carbon dioxide (PaCo2) and pH. ( 5 marks)

(b) Explain the mechanisms that give rise to central cyanosis. ( 5 marks)

M05Q3 A 26 year old male was found to have a collapse of the entire lower lobe of the left lung. His arterial pH was 7.32, PO2 was 58 mmHg and PCO2 was 73 mmHG when he was breathing room air at atmospheric pressure.a. Explain how the arterial blood gas results may come about.(5m)b. If this patient was given an air mixture with 30% oxygen to breathe,

how may this affect his arterial PO2. (5m)

A03A6 An adult male has emphysema where there is extensive destruction of the alveolar walls.(a) Describe the anatomical structures that constitute the alveola-capillary

membrane.(b) Explain how arterial partial pressure of oxygen (PaO2) may be affected

ifi) he exercise at the increasing levels of intensityii) his alveolar partial pressure of oxygen (PaO2) drop below

normal level.

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J02B7 An adult patient with left ventricular failure was noted to have interstitial oedema of the lungs. a. Describe the important features of the pulmonary circulation in comparison with the systemic circulation. b. List the important structures in the pulmonary interstitium. c. Explain how interstitial oedema may develop in left ventricular failure.

M02A1 Explain how respiration may be affected in a. A patient with diabetic ketoacidosis. b. A patient with an arterial PCO2 of mmHg c. An individual breathing an air mixture with 15% oxygen.

M01B8 An extremely anxious patient was found to be hyperventilating before undergoing dental treatment.i. Describe the location and role of the respiratory center in generating

the respiratory rhythm under normal resting conditions.ii. Describe how the respiratory center may be affected by a brief period

of hyperventilation.M00B7 Describe the transport of C02 in blood. How many C02 content of blood be

affected in the following conditions:(i) acute, severe bronchoconstriction(ii) breathing frequency of 25 times per minute and tidal volume of

600 ml in an adult.J99A3 Explain how carbon dioxide produced by tissue metabolism is removed from the body.J99A5 Explain how the oxygen content of arterial blood may be affected by (a)

anaemia, and (b) carbon monoxide poisoning.A99B8 Describe the role of the central and peripheral nervous systems in the

regulation of respiration.J98A2 Describe how carbon dioxide is transported in the blood.A98B9 Describe and explain how each of the following conditions may affect arterial partial pressure of oxygen (Pa02), percent oxygen saturation of arterial blood (SaO2), and arterial oxygen content:

a) Anemiab) Hypoventilationc) Residence at a high altitude

J97A6 Describe and explain the changes which may be observed in arterial pC02,[HC03-] and pH when carbon dioxide retention occurs in a patient with chronic obstructive lung disease.

A97A6 Explain briefly how the delivery of oxygen to tissues may be affected by:a)feverb)cardiac failurec)pulmonary oedema

J86B9 Describe the role of central and peripheral chemoreceptors in the regulation of respiration at high altitudes.M94B8 Answer BOTH parts of the question:

a)Describe the transport of carbon dioxide by blood.b)Describe the factors that influence the compliance of the lungs.

J92Al Describe the physiological effects of a low arterial pressure of carbon dioxide.M92A1 Briefly describe how ventilation of the lungs may be affected by:

a)rapid, shallow respirationb)breathing through a wide-bored tube (eg. as in snorkeling)

J91A1 Briefly discuss the roles of chemoreceptors in the regulation of respiration.M91B2 Answer BOTH parts of the question.

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a)Describe the role of the vagus nerve and bronchial stretch receptors inregulating the volume and frequency of respiration.

b)With the aid of illustrations, describe how 1) a fall in plasma pH and 2) exposure to carbon monoxide affect the oxygen - haemoglobin dissociation curve.

6. Gastrointestinal Physiology

M06Q2 Briefly discuss gastric secretions under the following headings.(a) the name and source of these gastric secretions.(b) The different phases of gastric secretion.(c) How are each of these phases controlled?

M05Q6 A 60 year old man complained to his general practitioner that he had recently felt tired and listless. He also complained of longstanding symptoms of dizziness and sweating after meals. Five years previously he had undergone partial gastrectomy (removal of ¾ of his stomach) and at first had felt reasonably well. In the last 2 years however, he had become forgetful and had neglected to see his doctor for vitamin B12 injections.A. Discuss the function of the stomach. (10m)B. How may this surgery affect his digestion? (4m)C. Haematological examination shows macrocytic /megaloblastic

anaemia. Explain why this can occur. (6m)

A03A4 Outline the roles of pancreatic secretion in digestion and absorption.J02A5 Briefly discuss the control of

a. acid secretion in the stomachb. bile and pancreatic secretions

J02A3 Define glomerular filtration rate (GFR), list its determinants, and explain briefly how it is regulated in a healthy individual.

M02B8 Explain the following observations:a. Both the removal of the stomach and resection of the ileum may lead to macrocytic/ megaloblastic anemia (maturation failure type of anemia). b. Complete obstruction of the common bile duct can lead to excessive bleeding.

M02A2 Outline the processes of carbohydrate digestion. What are the final products of carbohydrate digestion and how are they absorbed?

M01A5 Explain how the duodenum can inhibit gastric emptying.M01A4 Describe how salivary composition changes with the rate of salivary secretion.M01B9 Describe the role of the pancreas in the process of digestion.M00B9 (a) Discuss how the small intestine is adapted for the absorption of nutrients.

(b) Write briefly on the functions of bile salts and explain how lecithin enhance bile function in the gastrointestinal tract.J99A1 Discuss the factors controlling the pancreatic secretion of enzymes and

bicarbonate.A99A3 Explain how gastrectomy (removal of stomach) may lead to a form of vitamin deficiency anemia.J98A3 Write briefly on the regulation of secretion and the functions of pancreatic

juice.A98A1 Give an account of the composition and functions of saliva.

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J97B9 Describe the functions of bile and the mechanisms controlling its formation and

secretion.A97A5 Explain how the stomach is normally protected from the acid in the gastric

secretion.A97A4 Describe briefly the physiological consequences of ingesting a large volume of water. (3 litres)M96A4 Discuss briefly the regulation of gastric acid secretion.M94A2 Describe the physiological actions of gastrin in the human gut.M93A5 Write briefly on the synthesis and functions of bile salts in the gastrointestinal tract.J92A4 Describe and explain the possible consequences of total gastrectomy

(removal of stomach).M92B2 Describe briefly how bile salts are produced. What is the physiological

"value" of the entero-hepatic circulation of the salts.J91 A5 With the aid of a diagram, explain how salivary secretion is regulated.M91B1 Give a detailed account of the digestion and absorption of fats in the

human gut.M90A5 Give a concise account on the physiological importance of gastrin in the

gastrointestinal tract (GIT) function.

7. Endocrine

M06Q5 Describe briefly the physiologic regulation of plasma calcium concentration.

M04B1 Explain the effects of insulin deficiency on carbohydrate , lipid and protein metabolism.

A03A2 Explain the roles of parathyroid hormone, calcitriol and calcitonin in calcium homeostasis.

A03B7 In a normal individual, plasma glucose concentration is maintained within a narrow range. Various endocrine hormones are involved in the optimal usage of glucose during the fasting and postprandial states.a) Explain how endocrine processes defend against hypoglycaemia and

hyperglycaemia, respectively.b) What are the effects of insulin deficiency on carbohydrate, lipid and

protein metabolisms?c) Compare and explain the variation in blood glucose levels with time

between a normal individual and a diabetic patient after drinking a solution of 100g glucose.

J02A4 Explain how iodine deficiency may lead to the development of goiter.M02B9 Explain the importance of maintaining the plasma glucose concentration

within a narrow range in a normal individual. Discuss the hormonal regulation of plasma glucose concentration during fasting and in the fed state.

M02A6 Explain the role of the testes as endocrine organs in: a. A male fetus. b. Male puberty.

M01B8 Describe the physiological consequences of a lack of insulin secretion from the pancreas in an adult.

M01A1 Give a short account of the physiological changes that occur after the thyroid gland is removed in an adult.

M00B8 A patient whom you are looking after is scheduled for major dental surgery. He informs you that he has been taking a significant amount of oral synthetic

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glucocorticoid (dexamethasone) for many years for an arthritic problem. Apre-operative assessment reveals that his blood sugar level is mildly

raised.(a) What do you expect his cortisol and ACTH levels to be? Explain.(b) Why is his blood sugar level mildly raised?(c) What will happen to his glucocorticoid function if he stops taking his

medication during and after surgery? Give reasons.(d) What are three important functions of glucocorticoids?

J99B9 (a) Describe the physiological roles of calcium.(b) How does the body maintain calcium homeostasis when calcium intake

in the diet is low?(c) What are the physiological consequences of Vitamin D deficiency on

bone?A99B7 (a) If the receptors for sensing calcium levels is defective, what are the

effects of the defect on calcium and parathyroid hormone concentrations in the blood and on bone physiology?(b) Briefly discuss the role of the endocrine system in the maintenance of

body fat.J98B9 Discuss the physiological adaptations in calcium homeostasis that will occur in an

individual taking a low calcium diet.A98B8 Give a detailed account of the hormonal regulation of growth.J97B8 Discuss the factors which affect plasma calcium concentration.J97A4 Briefly discuss the role of calcium ions in skeletal muscle excitation and

contraction.A97B9 Discuss the role of the renin-angiotensin system in the regulation of blood

pressure.J96A6 Give a short account of the factors that affect serum ionized calcium levels.M94A4 Discuss concisely the role of Vitamin D in calcium and phosphate

homeostasis.J93A3 Discuss the effect of growth hormone on growth and metabolism in the body.M93A1 Discuss the biological actions of cortisol in the body.J92B3 Describe the major physiological functions of cortisol and the regulation of its secretion in a normal person.M92A4 Describe briefly the physiological processes that determine the plasma

concentration of total and free ionized calcium. Name the hormones involved in raisin., in raising a low plasma calcium level back to normal.J91A2 Give a brief account of the functions of growth hormone.J91B3 Describe how the volume of extracellular fluid is regulated by changes in

renin and aldosterone secretions.M91A5 Outline the physiological processes which help maintain the concentration

of plasma calcium within the normal range.M90A3 Describe the physiological functions of androgens in the adult male.M90B2 Give an account of the endocrine regulation of blood glucose concentration.

8. Renal Physiology

M05Q2 A 65 year old female had a history of severe vomiting and diarrhoea for 2 days. On admission to the hospital she was noted to have a blood pressure of 70/40 mmHg, pulse rate of 112 per minute. In the next few hours, she was noted to have low urine output.

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a. Explain how a pulse rate of 112 per minute may arise in this female (5m)

b. Explain why her urine output is low. (5m)

M04C7 In health , the plasma sodium concentration usually lies between 135 and 150 mmol/L and rarely varies by more than ±2% despite wide variations in water and salt intake . Explain the physiology processes involved in maintaining the plasma sodium concentration within this narrow range.

A03B9 Identify which of the following five observation is/are likely to be seen in a patient who has had diarrhea for a few days. For each item you have identified as a possible consequence of diarrhea, explain concisely how it might have arisen.(a) A urinary sodium excretion of 10mmol/day (i.e. about 10% of dietary

sodium intake )(b) A urinary osmolality of 900mOsm/kg(c) A plasma sodium concentration of 130mmol/L (normal 135-150mmol/L)(d) An increased thirst sensation (e) A low plasma renin activity

M01A11 Briefly describe the role of the kidney in potassium homeostasis.M00A3 Explain how the sympathetic response to stress results in changes in the

glomerular filtration rate (GFR).J99A4 Briefly discuss how potassium is handled by the renal tubules.A99B9 An athlete training in an environment with a temperature of 30 degree

Celsius lost one and a half liters of sweat over several hours. Assuming that the sodium concentration of sweat is one third that of plasma, describe the physiological processes which would help restore water and sodium balance in the athlete.

J98A4 Outline the physiological effects of angiotensin 11. Explain how an angiotensin

converting-enzyme inhibitor (ACE inhibitor) is able to reduce blood pressure.A98B7 Discuss the physiological mechanisms involved in the conservation and

replenishment of body water.J97A5 The osmolality of the glomerular filtrate is similar to that of plasma. Explain how this isotonic fluid, as it passes through the renal tubules, may eventually emerge from the collecting duct (as urine) having osmolalities very different from that of the filtrate.A97A Describe the fate of bicarbonate ions (HC03-) in the glomerular filtrate of

an individual with normal kidney function.J96A5 Briefly discuss the role of the kidney in the regulation of potassium

homeostasis.M96A6 Explain how plasma osmolality is maintained within narrow limits in a normal

individual.M94B9 Answer BOTH parts of the question:

a)Explain why creatinine clearance but not urea clearance, is a good measure of

the glomerular filtration rate in a normal individual.

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b)When water intake is increased, the urine produced often becomes hypotonic

to plasma. Explain this observation.J93A6 Outline the factors that control anti-diuretic hormone (ADH) secretion and its

role in determining urine volume.J92A5 Briefly describe the role of the kidney in maintaining potassium homeostasis.M92B 1 Describe in detail the renal tubular handling of sodium and water. Explain why a

low plasma sodium concentration hyponatremia may sometimes be observed in

congestive heart failure.M90A2 Write short notes on the measurement of renal blood flow.

9. Reproduction Physiology

J02A1 Describe the sequence of events that take place during fertilization.M01A6 Describe the changes to the physiology of the reproductive system of a

normal 30 year-old female given an exogenous dose of oestrogen in a cyclical fashion (21 days treatment and 7 days off treatment).

A99A2 Discuss the role of androgens in(a) the sexual development of the male foetus(h) male pubertal development.

J98A5 Discuss the regulation of prolactin secretion.J97A 1 Describe briefly the physiological functions of the placentaA97A3 Describe briefly the development of the oocyte from oogonia till ovulation.M96B9 Describe the changes that occur during puberty in the male and the female.M94A6 Discuss the hormonal control of lactation following delivery.J93A3 Give a concise account of the relation of the anterior pituitary

gonadotrophic hormones to the monthly sexual cycle.M93A3 Give a brief account of the physiological changes occurring at puberty.M92A5 Briefly discuss the physiological functions of progesterone in the female.J91A6 Describe and explain the changes in levels of gonadotropins during a

normal menstrual cycle.M91A4/ Discuss the role of Sertoli cells in spermatogenesis.

10. Neurophysiology

M05Q7 A man suffered from a localized deep cut on the sole of his left foot as he ran to avoid being bitten by a dog.a. Explain how the central nervous system may control pain during the

escape from the animal. (10m)b. Explain the neural basis of hyperalgesia at the injured area. (10m)

M04B4 a. Define memory. What is the importance of temporal lobe and cerebellum to learning and memory?

b. Briefly describe an endogenous neural mechanism for control of pain.

A03A3 An aged man, who had a stroke, could not voluntarily move his right arm or leg. He also had difficulty in communicating. Given the above scenario, answer the following: a) What are the cortical areas affected and on which side?

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b) Concisely explain the role of cerebral cortex in voluntary movement.

c) Explain the two major types of language disturbances that may arise due to damage

M01A2 Concisely describe how we perceive colours. Explain whether colours of an object are clearly perceived in the dark.

M01A4 An alpha-1 adrenergic receptor agonist is administered to a normal individual. Describe how this may affect:iii. heart rateiv. cardiac outputv. arterial pressure

Give explainations for your answers.M01A3 Define pain. Briefly describe the characteristic features of:

a. Somatic painb. Neuropathic painc. Visceral pain

M00A1 (a) Briefly explain the hierarchical system of motor control.(b) Define learning and memory. Briefly explain the possible cellular

mechanisms of learning and memory.A99A5 Briefly describe the descending motor pathways and their role in muscle

control.J98A6 Briefly explain the following:

a) amplification of transducin during phototransductionb) faster conduction of action potential by myelinated axons.

A98A5 Explain the role of the stretch reflex and the Golgi tendon organs in theregulation of muscle tone.

A97B7 Answer both parts:(a)Draw a neural circuit to illustrate the flexor withdrawal reflex inresponse to a painful stimulus(b)What is the suggested role of the hippocampus in learning and memory? Briefly describe a possible cellular mechanism in the hippocampus which may be involved in learning and memory.

M96A1 Briefly explain the following:a) the analgesia due to the stimulation of large-diameter afferent nerve

fibres.b) The high acuity of the cone system of the eyec) The hypotonia observed in patients with cerebellar lesionsd) The adaptation of activity in a Pacinian corpuscle

J93A4 Give an account of reflexes, illustrating your answer with the stretch and cross extension reflexes.M93B8 Describe the physiological characteristics of pain receptor and give an account of how pain sensation is transmitted and modulated within the nervous system.J91B1 Discuss the roles of central nervous system in the maintenance of an

upright position.M90B1 What are the characteristics of chemical synapses? Give a concise account of synaptic inhibition and excitation.

11. Environmental Physiology

M00A5 Explain how an acid-base disturbance may arise following vomiting.J99B8 Describe the physiological mechanism that regulate body temperature.

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J96A4 Briefly describe the physiological mechanisms that are initiated when the body is cooled below approximately 37°C.

12. Oral Physiology

M00A6 Discuss in detail the functions of saliva.A98A1 Give an account of the composition and functions of saliva.M93B9 Discuss in detail how the oral environment contributes to the development

of dental caries.M92B3 Give an account of the functions of saliva and the regulation of its secretion.M91B3b Discuss the physiological factors involved in the development of dental caries.M90A6a Write short notes on:

i)halitosisii)how dental defects can affect speech

13. Autonomic Nervous System

J02B9 Draw and illustrate the functional organization of α-motor neurons in the spinal cord. Explain their regulation by descending pathways from the brain.

M02A5 What might be the effect of stimulation of the periaqueductal gray on the withdrawal reflex due to pain? Briefly explain your answer.

A99A1 Describe the autonomic control of micturition.A98A2 Discuss briefly the autonomic control of micturition.J92A6 Describe the role of the autonomic system in the regulation of gastrointestinal functions.

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