Carleton University · Web viewUses pyruvate carboxylase and PEP carboxykinase to convert pyruvate...

MOCK EXAM (FOR PRACTICE ONLY)COURSE: BIOL/BIOC 2200 A NAME: Brenna Gagliardi

It is most beneficial to you to write this mock midterm UNDER EXAM CONDITIONS. This means: • Complete the midterm in 100 minutes (1 hour & 40 minutes). • Work on your own and attempt every question. • Keep your notes and textbook closed.

After the time limit, go back over your work with a different colour or on a separate piece of paper and try to do the questions you are unsure of. Record your ideas in the margins to remind yourself of what you were thinking when you take it up at PASS.

The purpose of this mock exam is to give you practice answering questions in a timed setting and to help you to gauge which aspects of the course content you know well and which are in need of further development and review. Use this mock exam as a learning tool in preparing for the actual exam.

Please note:

Complete the mock exam before attending the take-up session. During the session you can work with other students to review your work.

Often, there is not enough time to review the entire exam in the PASS workshop. Decide which questions you most want to review – the Facilitator may ask students to vote on which questions they want to discuss in detail.

Facilitators will not distribute an answer key for mock exams . The Facilitator’s role is to help students work together to compare and assess the answers they have. If you are not able to attend the PASS workshop, you can work alone or with others in the class.

PASS worksheets are designed as a study aid only for use in PASS workshops. Worksheets may contain errors, intentional or otherwise. It is up to the student to verify the information contained within by attending the PASS workshop.

Good Luck writing the Mock Exam!!

Take-up Session #1: Thursday, December 17th, 2020 | 2:05-3:55 PM EST (2 hours)Take-up Session #2: Friday, December 18th, 2020 | 11:35-12:55 PM EST (2 hours)Office Hour: Friday, December 18th, 2020 | 2:05-2:55 PM EST (2 hours)Zoom Meeting Information:I will be emailing the Zoom meeting details (i.e. Zoom link, Meeting ID & Password) but it can also be found on your course’s CULearn page.Contact Information: [email protected]


1. Enzymes _________ reaction rates by _________ activation energy. They do this by coupling

otherwise __________ reactions.

a. Decelerate, decreasing, favourable

b. Accelerate, increasing, unfavourable.

c. Accelerate, increasing, favourable.

d. Decelerate, decreasing, favourable.

e. Accelerate, decreasing, unfavourable.

2. If ∆G°>0 then the reaction is…?

a. Spontaneous; Exergonic

b. Spontaneous; Endergonic

c. Non-Spontaneous; Exergonic

d. Non-Spontaneous; Endergonic

3. Levinthal’s Paradox illustrates that proteins must…?

a. only sample through limited conformations

b. fold by specific pathways

c. sample all possible conformations during folding

d. A and B

e. All of the above

4. Hydrophobic interactions are characteristic of:

a. Primary protein structure

b. Secondary protein structure

c. Tertiary protein structure

d. Quaternary protein structure

5. Which of the following reaction mechanisms would occur the slowest?

a. Has a unimolecular rate limiting step.

b. Has a bimolecular rate limiting step.

c. Has a termolecular rate limiting step.

d. There is not enough information to know.


6. We want to study the enzymatic activity of Glutaminase which converts L-glutamine to L-

glutamate which is hard to detect directly. However, another reaction using L-glutamate produces

a-ketoglutarate and NADH which is easy to measure. Which method of measuring enzyme activity

would work best?

a. Detect the accumulation of product.

b. Detect the utilization of substrate.

c. Detect the accumulation or utilization of a co-factor.

d. Detect the product of a coupled reaction.

e. None of the above.

7. Fill in the Blank: the catalytic efficiency is an estimate of how ________ an enzyme is and is

calculated as _______.

a. Perfect, K m

K cat

b. Imperfect, K catK m

c. Perfect, K catK m

d. Imperfect, K m

K cat


8. Which of the following monomers is a ketose sugar?

a. Glucose

b. Fructose

c. Galactose

d. Mannose

e. None of the above

9. Which of the following is not a function of Na+/K+-ATPase?

a. Maintenance of osmotic stability and cell volume

b. Maintenance of high intracellular K+

c. Maintenance of membrane potential

d. Creation of potentials in excitable cells


e. All are correct

10.Fill in the blanks: Metabolism occurs in steps because it allows for pathways to be ______ and

provides ______ in smaller amounts that can be used by the cell.

a. Inhibited, reducing power

b. Regulated, energy

c. Regulated, reducing power

d. Activated, energy


11.How does the cell bypass pyruvate kinase during gluconeogenesis?

a. Uses pyruvate carboxylase and PEP carboxykinase to convert pyruvate to PEP.

b. Uses glucose-6-phosphate to convert G6P to glucose

c. Uses fructose-1,6-bisphosphatase to convert fructose-1,6-bisP to F6P.

d. None of the above.

e. All of the above.

12.Fill in the blanks: Glycogen synthase is ______ while glycogen phosphorylase is ____ and ____.

a. Inhibited by G6P, Activated by ATP

b. Activated by G6P, Inhibited by ATP

c. Inhibited by ATP, Activated by G6P

d. Activated by ATP, Inhibited by G6P


13.The gene for an enzyme in the Citric Acid Cycle has been mutated such that there is a build-up of

a-Ketoglutarate in the cell. Which enzyme has been affected?

a. Citrate Synthase

b. Succinate Dehydrogenase

c. A-ketoglutarate dehydrogenase

d. Isocitrate dehydrogenase

e. None of the Above


14.The alanine cycle is used to transport ______ to the liver.

a. Nitrogen

b. Carbon

c. Amino Acids

d. Glycogen


15. Fill in the blanks: Generally (not always), carbohydrates in the body use the ______ while amino

acids use the _____.

a. D-conformation, L-conformation

b. L-conformation, D-conformation

c. L-conformation, L-conformation

d. D-conformation, D-conformation

16.Fill in the Blanks: In de novo purine synthesis the purine ring is synthesized by adding carbon and

nitrogen atoms to a pre-formed ____, that was synthesized as a part of ______?

a. Ribose-5-phosphate, Pentose Phosphate Pathway

b. Glucose-6-phosphate, Glycolysis

c. Oxaloacetate, Citric Acid Cycle

d. Pyruvate, Glycolysis


17.Where does the Krebs Cycle take place in an animal cell?

a. Cytosol

b. Nucleus

c. Mitochondrial Matrix

d. Mitochondrial Membrane

e. None of the Above.

18.Fill in the blanks: When Epinephrine and Glucagon are present in the liver glycogen synthesis is

_______ while glycogen degradation is ____.

a. Activated, Inhibited

b. Inhibited, Inhibited

c. Inhibited, Activated


d. Activated, Activated

19.Fill in the Blanks: In the Cori Cycle, ______ produced from pyruvate passes from the _____ to the

_____ where it is converted to _____.

a. Glucose, liver, blood, lactate

b. Lactate, blood, liver, glucose

c. G3P, blood, liver, lactate

d. Lactate, liver, blood, glucose


20.Fill in the Blanks: In the preparatory phase of glycolysis, _____ is converted into ____, requiring

the investment of _____.

a. Glucose, 1 molecule of G3P, 4 ATP

b. Glycogen, 2 molecules of G3P, 2 ATP

c. Glucose, 2 molecules of G3P, 4 ATP

d. Glycogen, 1 molecule of G3P, 2 ATP


21.Which of the following is incorrect about catabolism?

a. Catabolism encompasses the degradative and energy yielding reactions

b. Catabolism breaks down macromolecules to low molecular weight compounds.

c. In general, the reactions are reductive and consume reducing potential.

d. Cellular respiration is an example of a catabolic pathway.

e. All are correct

22.Fill in the Blanks: Glycerophospholipids are made up of a glycerol backbone, _____ attached to

the C1 and C2; and a ___ attached to the C3.

a. Phosphates, fatty acid

b. Fatty acids, phosphate

c. Fatty acids, carboxylic acid

d. Carboxylic acid, phosphate



23.Fill in the Blanks: Carbohydrates generally come into two forms ________ (with ___ carbons) and

______ (with ____ carbons)

a. Pyranose, 4, Furanose, 5

b. Pyranose, 5, Furanose, 4

c. Pyranose, 6, Furanose, 5

d. Pyranose, 5, Furanose, 6


24.Which of the following is incorrect about the Michaelis-Menten equation?

a. The MM equation concerns the reaction rate that is measured only when the equilibrium is

reached.

b. The MM equation concerns the reaction rate that is measure in the early reaction period.

c. It was derived using rate law.

d. All are correct

e. None are correct.

25.Fill in the Blanks: If the enzyme and substrate were perfectly complementary, the interaction

between enzyme and substrate would be _______ and so the reaction would not occur. Instead

the enzyme is complementary to the _______.

a. Unstable, product

b. Stable, transition state

c. Unstable, transition state

d. Stable, product


26.Which of the following does not affect reaction rates?

a. Concentration of reactants

b. Concentration of products

c. Temperature

d. Presence of Catalysts



27.Alpha-helices containing ______ amino acids on either end and ______ amino acids in the middle

can be used to span membranes.

a. Hydrophobic, Hydrophilic

b. Hydrophilic, Hydrophilic

c. Hydrophilic, Hydrophobic

d. Hydrophobic, Hydrophobic

28.Which of the following statements is incorrect about the equilibrium constant?

a. K eq≫1 then more products are present than reactants.

b. K eq≪1 then more reactants are present than products

c. K eq≫1 then more reactants are present than products

d. A and B

e. C and B

29.α-helices fit into the _______ groove of DNA while β-sheets fit well into the _______ groove of

DNA.

a. Major, Major

b. Major, Minor

c. Minor, Minor

d. Minor, Major

30.Which of the following statements is incorrect about thermodynamics?

a. Thermodynamics describes the relationship among various form of energy.

b. Thermodynamics help scientists to understand how metabolic processes are designed.

c. Thermodynamics can be used to determine if a process is possible.

d. Thermodynamics can be used to determine the rate at which processes will occur.

e. All are correct.

31.Below a pH of 2.20 most amino acids have a…

a. Ionized amino group

b. Protonated carboxylic acid group

c. Ionized carboxylic acid group

d. Protonated amino group



32.The Henderson Hasselbalch Equation is…

a. pK❑a=pH+log ¿¿

b. pH=pK❑a+log ¿¿

c. pH=pK❑a+log ¿¿

d. p Ka=pH+ log¿¿

e. pH=p Ka+ ln¿¿

33.The effectiveness of a buffer is determined by:

a. The pH of the solution; buffers work best within 3 pH units above and below the pKa.

b. The pH of the solution; buffers work best within 1 pH unit above and below the pKa.

c. The concentration of the buffer; the more present, the more the buffering capacity.

d. A and C

e. B and C

34.When an amino acid is in a basic solution…

a. The carboxylic acid ionizes and the pH of the solution increases.

b. The carboxylic acid ionizes and the pH of the solution decreases.

c. The amino group is protonated and the pH of the solution increases.

d. The amino group is ionized and the pH of the solution decreases.

e. The carboxylic acid is protonated and the pH of the solution increases.

35.Fill in the Blank: The various elementary steps in a reaction mechanism proceed at

_____________. The slowest step is called __________.

a. different rates, rate-limiting step

b. the same rate, rate-determining step

c. different rates, rate-determining step

d. A and C



36.Which of the following enzyme is matched with the proper enzyme class?

a. Lactate Dehydrogenase Oxidoreductases

b. Alanine Transferase Transferases

c. Pyruvate Decarboxylase Lyases

d. L-glutamine Synthetase Ligases

e. All are correctly matched.

37.Which of the following is incorrect about Kcat?

a. It is called the Turnover Number

b. It is the amount of time required for an enzyme to convert 1 substrate molecule to the

product.

c. It is the maximum number of substrate molecules converted to product per second by each

active site.

d. A and B

e. A and C

38.Match the correct form of enzyme inhibition with the diagram.

A) B) C) Figures 5-8 Principles of Biochemistry, 4/e @2005 Pearson Prentice Hall, Inc.

a. A Competitive, B Uncompetitive, C Noncompetitive

b. A Uncompetitive, B Noncompetitive, C Competitive

c. A Noncompetitive, B Competitive, C Uncompetitive

d. A Competitive, B Noncompetitive, C Uncompetitive



39.Fill in the Blanks: In a disaccharide the glycosidic bond forms between the hemiacetal hydroxyl

group at the ____ of one sugar and the hydroxyl group at the ___ of another sugar.

a. C1, C2

b. C4, C2

c. C1, C4

d. C1, C6


40.Which of the following in incorrect about membrane transport?

a. Primary active transport is powered by a direct source of energy as ATP, light, or electron

transport.

b. Secondary active transport is driven by an ion concentration gradient.

c. Transport requires ATP to move a solute down its concentration gradient.

d. All are correct.


41.Which of the following is incorrect about anabolism?

a. Anabolism encompasses the biosynthetic and energy yielding reactions.

b. Anabolism builds macromolecules from low molecular weight compounds.

c. In general, the reactions are reductive and consume reducing potential.

d. Photosynthesis is an example of an anabolic pathway.

e. All are correct

42.What is the free energy change of ATP hydrolysis?

a. 32 kJ/mol

b. -48 kJ/mol

c. 48 kJ/mol

d. -32 kJ/mol

e. -30 kJ/mol


43.Which of the following is not used to regenerate NAD+ in a cell?

a. NADH is reduces pyruvate to lactate

b. Acetaldehyde is oxidized by NADH to form ethanol.

c. Mitochondrial oxidation of NADH to NAD+

d. All are correct.


44.Fill in the Blacks: Hexokinase is ___________ by _________.

a. Activated, G6P

b. Inhibited, G3P

c. Activated, G3P

d. Inhibited, G6P


45.Fill in the blanks: Glycogenin has a _______ side-chain that is crucial to its function.

a. Tryptophan

b. Tyrosine

c. Threonine

d. Cysteine



Fumarate in the cell. Which enzyme has been affected?

a. Succinyl-CoA Synthetase


c. Fumarase

d. Aconitase


47.Fill in the blanks: When insulin is present in the liver glycogen synthesis is ______ while glycogen

degradation is _______.

a. Activated, Inhibited

b. Inhibited, Inhibited

c. Inhibited, Activated


d. Activated, Activated

48.What are the 3 enzymes in the Citric Acid Cycle that control the reaction rate of the pathway?

a. Citrate Synthase, Aconitase, Isocitrate Dehydrogenase

b. Citrate Synthase, Isocitrate Dehydrogenase, a-Ketoglutarate dehydrogenase

c. Aconitase, Isocitrate Dehydrogenase, a-Ketoglutarate Dehydrogenase

d. A-ketoglutarate Dehydrogenase, Succinyl-CoA Synthetase, Succinate dehydrogenase


49. In fatty acid synthesis the formation of what intermediate inhibits beta-oxidation?

a. Acetyl-CoA

b. Malonyl-CoA

c. Palmitoyl-CoA

d. Citrate


50.Fill in the blanks: ATP synthesis is driven by the energy stored in _________. This is called

_________.

a. Chemical Gradient, Electron Motive Force

b. Electrochemical Gradient, Proton Motive Force

c. Electrical Gradient, Proton Motive Force

d. Electrochemical Gradient, Electron Motive Force



succinate in the cell. Which enzyme has been affected?

a. Succinyl-CoA Synthetase


c. Fumarase

d. Aconitase



52.Fill in the Blanks: In odd chain beta oxidation fatty acids are converted to ________ instead of

_______, which can be converted to _______ and used in the citric acid cycle.

a. Propionyl-CoA, Acetyl-CoA, Succinate

b. Propionyl-CoA, Acetyl-CoA, Succinyl-CoA

c. Acetyl-CoA, Propionyl-CoA, Succinate

d. Acetyl-CoA, Propionyl-CoA, Succinyl-CoA


53.What is the correct order of steps in beta-oxidation?

a. Dehydration > Dehydration > Hydration > C-C Cleavage

b. Hydration > Dehydration > C-C Cleavage > Dehydration

c. Dehydration > Hydration > Dehydration > C-C Cleavage

d. C-C Cleavage > Hydration > Dehydration > Dehydration


54.What is the correct order of enzymes in Glycogen catabolism?

a. Glycogen Phosphorylase, Glycogen Debranching Enzyme, Phosphoglucomutase

b. Glycogen Debranching Enzyme, Phosphoglucomutase, Glycogen Phosphorylase

c. Phosphoglucomutase, Glycogen Debranching Enzyme, Glycogen Phosphorylase

d. Glycogen Phosphorylase, Phosphoglucomutase, Glycogen Debranching Enzyme


55.Which of the following does not explain why all nine intermediates of glycolysis are

phosphorylated?

a. Prevents them from diffusing out of the cell.

b. Phosphates are essential components in conserving metabolic energy.

c. Binding energy of phosphate group lowers the EA of enzymatic reactions.

d. All are correct.



56.ATP carries an activated ____ group and Acetyl-CoA carries an activated _____ group.

a. Acetyl, Carboxyl

b. Carboxyl, Phosphoryl

c. Phosphoryl, Acetyl

d. Acetyl, Phosphoryl


57.Which of the following is incorrect?

a. Amylopectin and Glycogen contain α (1→6) glycosidic bonds.

b. Amylose only contains α (1→4) glycosidic bonds.

c. Amylopectin contains more α (1→6) glycosidic bonds than glycogen.

d. All are correct

e. None are correct

58.What is incorrect about membrane fluidity?

a. At lower temperatures, the membrane is less fluid.

b. Kinks in fatty acid chains, allow the membrane to be more tightly packed.

c. Cholesterol is important in maintaining membrane fluidity.

d. All are correct

e. None are correct

59.Fill in the Blanks: Carbohydrates are a large class of natural occurring polyhydroxyl ________ and

_______.

a. Esters, Ketones

b. Ketones, Aldehydes

c. Aldehydes, Esters

d. Ketones, Amides



60.Fill in the Blanks: ____ is the measure of the affinity of an enzyme for its substrate. It can be

calculated as the ____ required to achieve ______.

a. Km, substrate, ½ Vmax

b. Vmax, enzyme, Km

c. Km, enzyme, ½ Vmax

d. Kcat, substrate, Vmax


61.Which of the following is incorrect about catalysts?

a. Catalysts are specialized to perform specific chemical reactions.

b. Catalysts increase the rate of reaction by increasing the EA.

c. Catalysts are specialized to work in specific environments.

d. Catalysts do not change the direction of the reaction.

e. All are correct.

62.Which of the following is incorrect about enzymes?

a. Change the free energy of the reaction.

b. Conduct a specific reaction with no side products.

c. Reduces the time required to reach equilibrium.

d. Stabilizes the transition state

e. All are correct.

63.Fill in the blank: The rate of reaction can be monitored by measuring the ___________ in the

concentration of the reaction ___________ with time.

a. Decrease, product

b. Increase, reactant

c. Increase, product

d. B and C

e. A and B


64.Living cells are ________. They are in a steady state, meaning a constant flow of ________,

prevents them from becoming ________.

a. Stable, Water, Disorganized

b. Unstable, Ions, Organized

c. Unstable, Energy, Disorganized

d. Stable, Energy, Organized

e. Unstable, Ions, Disorganized

65.What is the difference between saturated and unsaturated fatty acids?

a. Saturated fatty acids contain some double carbon-carbon bond while unsaturated fatty

acids contain only single carbon-hydrogen bonds.

b. Saturated fatty acids are composed of more hydrogen atoms than unsaturated fatty acids.

c. Saturated fatty acids contain only single carbon-carbon bonds while unsaturated fatty acids

contain some carbon-carbon double bonds.

d. B and C

e. A and C

66.What is the correct order of the solid-phase peptide synthesis method?

a. Activation, coupling, deprotection

b. Deprotection, activation, coupling

c. Coupling, deprotection, activation

d. Deprotection, coupling, activation

67.Hydrogen bonding between the backbone of amino acids in a polypeptide chain are characteristic

of:

a. Primary protein structure

b. Secondary protein structure

c. Tertiary protein structure

d. Quaternary protein structure


68.Which of the following is incorrect about Histidine?

a. Its R-group is a weak acid

b. It is often found in active sites

c. It is hydrophobic

d. It can bind metal ions such as zinc, nickel, and copper.

e. A and C

69.Given the chemical equation: 2 A+3B⇌C+4D. What is the appropriate representation of K eq?

a. K eq=[A ]3 [B ]2

[C ]4[D ]

b. K eq=[C ]2 [D ]3

[A ] [B ]4

c. K eq=[C ] [D ]4

[A ]2 [B ]3

d. K eq=[A ]2 [B ]3

[C ] [D ]4


70.Fill in the Blanks: Proteins destined for degradation are labeled with ____ and degraded by _____.

a. Acetyl groups, Proteases

b. Methyl groups, Proteasomes

c. Ubiquitin, Proteasomes

d. Carboxyl groups, Proteases


71.Glycogen is principally stored in the _______ of muscle and liver cells.

a. Cytosol

b. Nucleus

c. Mitochondrial Matrix

d. A Vesicle



72.Fill in the blanks: In the payoff phase of glycolysis, ______ is converted into ______, which yields

____ and ____.

a. Glucose, pyruvate, 4 ATP, 2 NADH

b. G3P, acetyl-CoA, 2 ATP, 2 NADH

c. Glucose, acetyl-CoA, 2 ATP, 4 NADH

d. G3P, pyruvate, 4 ATP, 2 NADH


73.The Isoelectric point of an amino acid is the ____ at which the majority of its molecules in solution

have _____________.

a. pKa, no net charge

b. pH, no net charge

c. pH, positive charge

d. pKa, negative charge

e. pH, negative charge

74.Above a pKa of 9.52 most amino acids have a…

a. Ionized amino group

b. Protonated carboxylic acid group

c. Ionized carboxylic acid group

d. Protonated amino group

e. A and B

75.Fill in the blanks: _________ pathways for catabolism and anabolism. Differences allow for ____

of catabolic and anabolic pathways separately.

a. Amphipathic; activation

b. Amphibolic, regulation

c. Amphipathic, regulation

d. Amphibolic, inhibition



76.Fill in the Blanks: The pyruvate dehydrogenase complex is inhibited by _____ which competes

with ___ for binding to E3 and ____ which competes with ____ for binding to E3.

a. NAD+, NADH, CoA, Acetyl-CoA

b. NADH, NAD+, Acetyl-CoA, CoA

c. NAD+, NADH, Acetyl-CoA, CoA

d. NADH, NAD+, CoA, Acetyl-CoA


77.Protein X is found to insoluble in water, mechanically strong and flexible. This is most likely a…?

a. Globular Protein

b. Fibrous Protein

c. Membrane Protein

d. Motor Protein

78.Which of the following enzymes is incorrectly matched with the reaction it catalyzes:

a. Hexokinase transfer of a phosphoryl group from ATP to Glucose.

b. Phosphofructokinase transfer of a phosphoryl group from F6P to ATP.

c. Pyruvate Kinase transfer of high-energy phosphoryl group to ADP yielding ATP.

d. All are correct.

e. None


Use the following diagram of a polypeptide to answer the next 2 questions.

Figure 1. https://www.chegg.com/homework-help/questions-and-answers/polypeptide-shown-circle-peptide-bonds-polypeptide-amino-acid-

indicate-polar-non-polar-ele-q29958159

79.The third amino acid residue from the N-terminus is…

a. Alanine

b. Glycine

c. Threonine

d. Valine


80.The fourth amino acid residue from the N-terminus is…

a. Aspartic Acid

b. Glutamine

c. Asparagine

d. Glutamic Acid



GOOD LUCK ON YOUR EXAM!

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