BY GROUP 3ANNISA FADILAH TRG

DURRIYAH LBSLETTY NAINGGOLANPUTRI DIAN HAMIANSOHMIYATI LINGGA

Biochemistry:“PROTEIN”

What is Protein??

Protein is a macro nutrient composed of monomer form amino acids that is necessary for the proper growth and function of the human body.

Amino acids are small molecules that contain carbon, hydrogen, oxygen, and nitrogen atoms; two also contain sulfur atoms.

A chain amino acids is called a polypeptide chain

The structure of Amino acid

How can we get Protein?

A set of essential amino acid we obtained from animal and/or vegetable protein sources.

Legumes

Peanut

A 1-cup serving of raw peanuts contains 828 calories and 38 grams of protein. Peanuts lack the essential amino acid L-methionine, but contain high levels of the other essential amino acids, including L-lysine.

Cereal and grains

Cereal and grains

Cereal rich of carbohydrates, complete protein, low fat, and rich of rough fiber.

Animal

Seafood (compelete protein)

A 3.5 ounce salmon filet contains about 27 grams of protein, while a single six ounce can of tuna holds a whopping 40 grams of the body-building macronutrient.

Fruits

Fruits

Fruits can be a good source of protein, though they tend to provide less than vegetables, beans, and legumes. When looking for protein, dried fruits and berries are best.

Vegetables

Vegetables

Eat more of green vegetables, because green vegetables contain more protein than other vegetables. So the protein needed in our body enough to get.

Functions of Protein

Biological functionStructural proteins , has function to

support.

(Microtubule and microfi lament proteins form supporting fibers inside cells; collagen and other proteins surround and support animal cells; cell wall proteins support plant cells.)

Enzymatic proteins, Increase the rate of biological reactions.

e.gDNA polymerase increases the rate of

duplication of DNA molecules; RuBP carboxylase/oxygenase increases the rates of the first synthetic reactions of photosynthesis; the digestive enzymes lipases and proteases increase the rate of breakdown of fats and proteins, respectively.

Membrane Transport proteins, To Speed up movement of substances across biological membranes.

E.g :Ion transporters move ions such as Na, K,

and Ca2 across membranes Glucose transporters move glucose into

cells Aquaporins allow water molecules to move

across membranes.

Motile proteins, to produce cellular movements.

e.g.: Myosin acts on microfilaments to produce

muscle movementsdynein acts on microtubules to produce the

whipping movements of sperm tails, flagella, and cilia

kinesin acts on microtubules of the cytoskeleton

Regulatory proteins, Promote or inhibit the activity of other cellular molecules.

e.g.:Nuclear regulatory proteins turn genes on

or off to control the activity of DNA.Protein kinase add phosphate groups to

other proteins to modify their activity.

Receptor proteins, to bind molecules at cell surface or within cell; some trigger internal cellular responses.

e.g.:Hormone receptors bind hormones at the

cell surface or within cells and trigger cellular responses.

LDL receptors bind cholesterol-containing particles to cell surfaces.

Storage proteins, Hold amino acids and other substances in stored form.

e.g.:Ovalbumin is a storage protein of eggs Apolipoproteins hold cholesterol in stored

form for transport hrough the bloodstream.

Venoms and toxins, Interfere with competing organisms Interfere with competing organisms.

e.g.:Ricin is a castor-bean protein that stops protein synthesis.

Bungarotoxin is a snake venom thatcauses muscle paralysis.

Physical funtion

Proteins form the basis of cells, which come together to form organs, muscle tissue, bones, skin, hair and nails.

help organize your cells into separate tissues and they can protect the body as well.

for example, specialized proteins tightly connect one skin cell to another to create a cohesive barrier against the outside environment.

Classification of Protein

Based on Their needed in our body.o Essential (very needed, cannot

synthesize, cosume via diet)o Conditionally essential (not always

needed)ex: a young and growing individual,

or during illness.o Non-essential amino acids ( needed,

can synthesize)

Essential amino acids:

• Histidine, Isoleucine, Valine , Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan

Non Essential amino acids: Alanine, Asparagine, Aspartic acid, and

Glutamic acid.Conditionally amino acids:

Arginine, Cysteine, Glutamine, Tyrosine, Glycine, Ornithine, Proline, and Serine.

•Based on the sidegroup

Structure of Protein.

Proteins have four level of structure. each level has different characteristics and degrees of structural complexity to the molecule. Primary structure is the particular and sequence

of amino acids forming a polypeptide.

secondary structure is produced by the polypeptide chain twists into coil (helix) and turns of the amino acid chain.

Tertiary structure is the folding of the amino acid chain into a functional domain such as a barrel or pocket with its secondary structures, into the overall three-dimensional shape of a Protein. In this example, the coils of a globin

chain form a pocket

Quaternary structure, when present, refers to the arrangement of polypeptide chains in a protein that is formed from more than one chain. Hemoglobin, shown here, consists of four globin chains ( brown and blue). Each globin pocket now holds a heme group (red ).

Disease and clinical diagnose caused by protein

Changes in a protein’s shape may have drastic consequences to health. And can cause disease.

If proteins get denature, it will affect to their function.

Disease caused by the changing shape of protein:Prion diseases (Prions are misfolded proteins), including mad cow disease (bovine

spongiform encephalitis, or BSE) in cattle. Affect the nervous system

The symptoms: hard to diagnose until it has nearly run its

course.people have symptoms related to the nervous

systemdepression and loss of coordinationDementia develops (the loss of mental

functions such as thinking, memory, and reasoning that is severe enough to interfere with a person's daily functioning

Creutzfeldt-Jakob disease in humans CJD is a degenerative neurological disorder (brain

disease) that is incurable and invariably fatal.The symptoms:• leading to memory loss, personality changes and

hallucinations• physical problems such as speech impairment, jerky

movements (myoclonus), balance and coordination dysfunction (ataxia), changes in gait, rigid posture, and seizures.

• CJD can be fatal within months or even weeks

How can diagnose?

Standard diagnostic tests include, A spinal tap (rule out common causes of

dementia ) Electroencephalogram (EEG) to record the

brain’s electrical patternComputerized tomography of the brain ( know

the symptoms caused by another problem like can stroke or tumor)

Magnetic resonance imaging (MRI) brain scans also can reveal characteristic patterns of brain degeneration that can help diagnose CJD.

Scrapie in sheep,is a fatal, degenerative disease affecting the central nervous system of sheep and goats. 

The diseases classified as transmissible spongiform encephalopathies (TSE). 

The disease apparently causes an itching sensation in the animals.

Clinical sign and diagnosis

The symptoms:There may be behavioural changes and

maybe an increase in chewing movements.Ataxi.a and neurological signs then develop.Some sheep scratch excessivelyshow patches of wool loss and lesions on the

skin.weight loss, anorexia, lethargy and possibly

death.