Proteins

Question 1

What elements can be found in some proteins?

Answer 1

Few proteins contain other elements such as I, Cu, Mn, Zn, and Fe.

Question 2

What is the molecular weight range of protein molecules?

Answer 2

Protein molecules have a high molecular weight ranging from 5,000 to 2,500,000.

Question 3

What are the monomers of proteins called?

Answer 3

The small units that proteins can be broken down into are called amino acids.

Question 4

How many standard amino acids are proteins made up of?

Answer 4

Proteins are made up of 20 standard amino acids in different sequences and numbers.

Question 5

What is the main structural role of proteins in the body?

Answer 5

Proteins are the main structural components of the cytoskeleton and are the sole source to replace nitrogen in the body.

Question 6

What are enzymes?

Answer 6

Biochemical catalysts known as enzymes are proteins.

Question 7

What role do immunoglobulins play in the body?

Answer 7

Immunoglobulins serve as the first line of defense against bacterial and viral infections.

Question 8

What are some examples of proteins that serve as hormones?

Answer 8

Several hormones are protein in nature.

Question 9

What are contractile proteins and give examples?

Answer 9

Contractile proteins, such as actin and myosin, help in the movement of muscle fibers.

Question 10

What is the function of transport proteins?

Answer 10

Transport proteins carry out the function of transporting specific substances either across the membrane or in body fluids.

Question 11

What do storage proteins do?

Answer 11

Storage proteins bind with specific substances and store them, e.g., iron is stored as ferritin.

Question 12

What are chromoproteins?

Answer 12

Chromoproteins are proteins with colored prosthetic groups, such as hemoglobin and flavoproteins.

Question 13

What is the classification of proteins based on composition?

Answer 13

Proteins can be classified as simple proteins, conjugated proteins, and derived proteins.

Question 14

What are simple proteins?

Answer 14

Simple proteins yield only amino acids and no other major organic or inorganic hydrolysis products.

Question 15

What are conjugated proteins?

Answer 15

Conjugated proteins yield amino acids and other organic and inorganic components.

Question 16

What are lipoproteins?

Answer 16

Lipoproteins are proteins loosely combined with lipid components, occurring in blood and on cell membranes.

Question 17

What are metalloproteins?

Answer 17

Metalloproteins contain a metal ion as their prosthetic group, such as ferritin containing Fe.

Question 18

What is the primary structure of a protein?

Answer 18

The primary structure is the linear sequence of amino acids held together by peptide bonds.

Question 19

What defines the secondary structure of a protein?

Answer 19

The secondary structure refers to the local structure of a polypeptide chain, determined by hydrogen bonds.

Question 20

What is the tertiary structure of a protein?

Answer 20

The tertiary structure is the overall three-dimensional shape formed by the folding of the polypeptide chain.

Question 21

What is the quaternary structure of a protein?

Answer 21

The quaternary structure refers to a complex of two or more separate peptide chains held together by interactions.

Question 22

What are the general properties of proteins?

Answer 22

Proteins are tasteless, odourless, and their viscosity varies with concentration and type.

Question 23

What is the isoelectric point (pI) of proteins?

Answer 23

At the isoelectric pH, a protein exists as a dipolar ion, carrying equal numbers of positive and negative charges.