Part 1

Question 1

What are proteins?

Answer 1

Proteins are large molecules containing Carbon, Hydrogen, Oxygen, and Nitrogen. Some proteins also contain sulphur.

Question 2

What percentage of a lean adult body is protein?

Answer 2

A lean adult body normally contains 12-18% protein.

Question 3

How is protein stored in the body?

Answer 3

Only small amounts of protein are temporarily stored in the body, which can be quickly used up on demand compared to carbohydrates and lipids.

Question 4

What do the symbols H, N, C, O, and R represent in proteins?

Answer 4

H = Hydrogen, N = Nitrogen, C = Carbon, O = Oxygen, R = Variable Side Chain.

Question 5

• is a covalent bond that connects each amino acid to another amino acid that is formed through dehydration reaction. The long chains of amino acids are called polypeptides.

Answer 5

PEPTIDE BOND (Amide Linkages)

Question 6

• A protein is a natural polymer composed of amino acid monomers joined together

Answer 6

PEPTIDE BOND (Amide Linkages)

Question 7

The long chains of amino acids

Answer 7

polypeptides

Question 8

• An index used to determine whether physiological requirements are being met.

Answer 8

NITROGEN BALANCE

Question 9

Nitrogen ingested
(Primarily as protein)
-
Nitrogen Excreted
(Primarily as urea)

Answer 9

Nitrogen balance

Question 10

0 (Nitrogen equilibrium)

Answer 10

Nitrogen balance

Question 11

protein degradation

Answer 11

Protein synthesis

Question 12

protein synthesis > protein degradation

Answer 12

Positive Nitrogen Balance

Question 13

protein synthesis < protein degradation

Answer 13

Negative Nitrogen Balance

Question 14

• Most proteins do not occur as long chains inside the cells unlike polysaccharides. Instead, they are folded into three - dimensional structures, which determine the structures and kinds of amino acids.

Answer 14

PROTEIN FOLDING

Question 15

Types of Protein Structures

Answer 15

Primary Structure
Secondary Structure Tertiary Structure
Quaternary Structure

Question 16

• The unique sequencing of amino acids in a polypeptide chain.

Answer 16

1. Primary (1°) Structure

Question 17

• Localised folding in some regions of the chain of amino acids - alpha helix and beta sheet

Answer 17

2. Secondary (2°) Structure

Question 18

• Overall shape of a polypeptide as a result of interactions of the R Group and water

Answer 18

3. Tertiary (3°) Structure

Question 19

• Arrangement of two or more polypeptide chains relative to one another.

Answer 19

4. Quaternary (4º) Structure

Question 20

2 PROTEIN CLASSIFICATION BASED ON THEIR
CHEMICAL COMPOSITION

Answer 20

1. SIMPLE PROTEINS
2. COMPLEX PROTEINS

Question 21

• Only made up of amino acids

Answer 21

SIMPLE PROTEINS

Question 22

• These proteins have other chemical components in addition to amino acids
- organic or inorganic additional components known as “prosthetic groups”

Answer 22

COMPLEX PROTEINS

Question 23

PROSTHETIC
GROUP
-Heme Unit

SPECIFIC EXAMPLE
-Haemoglobin/Hemoglobin
Myoglobin

FUNCTION
-Carries oxygen in the blood Binds oxygen in muscles

Answer 23

Haemoproteins/
Hemoproteins

Question 24

PROSTHETIC
GROUP
-Lipid

SPECIFIC EXAMPLE
-Low-density Lipoprotein (LDL)
High-density Lipoprotein (HDL)

FUNCTION
-Carries Lipid

Answer 24

Lipoproteins

Question 25

PROSTHETIC GROUP -Carbohydrates SPECIFIC EXAMPLE -Gamma Globulin Mucin Interferon FUNCTION -Antibody Lubricant in mucous secretions Antiviral protection

Answer 25

Glycoproteins

Question 26

PROSTHETIC GROUP -Phosphate Group SPECIFIC EXAMPLE -Glycogen Phosphorylase FUNCTION -Enzyme in glycogen phosphorylation

Answer 26

Phosphoproteins

Question 27

PROSTHETIC GROUP -Nucleic Acid SPECIFIC EXAMPLE -Ribosomes -Viruses FUNCTION -Site for protein synthesis in cells Self-replicating, infectious complex

Answer 27

Nucleoproteins

Question 28

PROSTHETIC GROUP -Metal Ion SPECIFIC EXAMPLE -Iron - ferritin -Zinc - alcohol dehydrogenase FUNCTION -Storage complex for iron -Enzyme in alcohol oxidation

Answer 28

Metalloproteins

Question 29

PROTEIN CLASSIFICATION BASED ON SHAPE

Answer 29

1. FIBROUS PROTEINS 2. GLOBULAR PROTEINS

Question 30

• These proteins are spiral and helical and are cross linked by disulphide and hydrogen bonds

Answer 30

FIBROUS PROTEINS

Question 31

HIGH PROTEIN VEGETABLES (RANKED FROM HIGHEST TO LOWEST)

Answer 31

GREEN PEAS SPINACH ARTICHOKES CORN AVOCADO ASPARAGUS BRUSSELS SPROUTS MUSHROOMS KALE POTATOES

Question 32

• They represent about 25-30% of all proteins among vertebrates.

Answer 32

Collagen

Question 33

• They are found in different tissues and organs, including tendons and the organic matrix of bone - in which they are present in very high percentages.

Answer 33

Collagen

Question 34

COLLAGEN RICH FOODS (FOR SKIN)

Answer 34

Berries Leafy Greens Citrus Fruits Nuts and Seeds Soy Products Tomatoes Avocado

Question 35

COLLAGEN RICH FOODS (FOR SKIN)

Answer 35

Berries Leafy Greens Citrus Fruits Nuts and Seeds Soy Products Tomatoes Avocado

Question 36

• They constitute almost the entire dry weight of nails, claws, beak, hooves, horns, hair, wool, and a large part of the outer layer of the skin.

Answer 36

a -Keratins

Question 37

• This protein provides elasticity to the skin and blood vessels due to its random coiled structure, different from the structures of collagen and a - keratin.

Answer 37

Elastin

Question 38

• Most of the proteins belong to this class, in which they have a compact and spherical structure and more complex than fibrous proteins.

Answer 38

GLOBULAR PROTEINS

Question 39

They are generally soluble in water but can also be found inserted into biological membranes (transmembrane proteins). Hence, in a hydrophobic environment.

Answer 39

GLOBULAR PROTEINS

Question 40

PROTEIN CLASSIFICATION BASED ON FUNCTION

Answer 40

Types: Enzymes Transport Structural Hormones Defence Contractile Storage

Question 41

EXAMPLES -Digestive enzymes: Amylase, lipase, pepsin, trypsin FUNCTIONS -Serve as catalysts in biochemical reactions such as digestive enzymes, which aid in digestion of food by breaking down nutrients to monomers.

Answer 41

Enzymes

Question 42

EXAMPLES -Haemoglobin, Albumin FUNCTIONS -Carry substances in the blood or lymph throughout the body.

Answer 42

Transport

Question 43

EXAMPLES -Actin, Tubulin, Keratin FUNCTIONS -Construct different structures like the cytoskeleton, hair, and nails.

Answer 43

Structural

Question 44

EXAMPLES -Insulin, thyroxine FUNCTIONS -Coordinate the activity of different body systems

Answer 44

Hormones

Question 45

EXAMPLES -Immunoglobulins (Antibodies) FUNCTIONS -Protect the body from invading pathogens

Answer 45

Defence

Question 46

EXAMPLES -Actin, myosin FUNCTIONS -Effect of muscle contraction - for movement

Answer 46

Contractile

Question 47

EXAMPLES -Legume storage of proteins, egg white (albumin) FUNCTIONS -Provide nourishment in early development of the embryo and the seedling.

Answer 47

Storage

Question 48

IMMUNOGLOBULINS

Answer 48

IgA IgD IgE IgG IgM

Question 49

Found in mucous, saliva, tears, and breastmilk Protects us against pathogens Transferred to an infant through breastmilk and colostrum.

Answer 49

IgA

Question 50

Part of the B cell receptor - helps them to start the immune response. Activates basophils and mast cells

Answer 50

IgD

Question 51

Protects against parasitic worms. Responsible for allergic reactions. Found mainly on tonsils, skin and mucous membranes.

Answer 51

IgE

Question 52

Secreted by plasma cells in the blood Able to cross the placenta into the fetus - important in the immunity of newborn

Answer 52

IgG

Question 53

May be attached to the surface of a B cell or secreted into the blood - with strong agglutinating ability Responsible for early stages of immunity.

Answer 53

IgM

Question 54

• A protein is defined by its 1°, 2°, and 30 structures. These give proteins certain identifying properties - biological, enzymatic, solubility, ionic, reactivity of side group, molecular weight, size, native structure.

Answer 54

Denaturation of Proteins

Question 55

-is the result of any changes in the native structure of proteins, which is caused about by breaking of any bond except the peptide bond.

Answer 55

Denaturation of Proteins