Biomolecules (Chemistry)

Question 1

The correct statement about peptides and proteins is

Accepted Answer

In β-pleated sheet structures, peptide chains are held together by intermolecular hydrogen bonds. In a β-pleated sheet the chains lie side by side and are held by hydrogen bonds BETWEEN different chains, which is what makes them intermolecular. The others fail on detail: two or more subunits is the quaternary structure, not tertiary; many biologically active proteins have no quaternary structure at all; and the α-helix is a right-handed screw.

Answer

Tertiary structure of proteins has two or more polypeptide subunits

Answer

Only the proteins having a quaternary structure are biologically active

Answer

In α-helices, the polypeptide chain is twisted into a left-handed screw (helix) through intramolecular hydrogen bonds

Question 2

Match the vitamins in List I with their sources in List II. Choose the correct answer from the options given below. A. vitamin A B. vitamin B₁₂ C. vitamin E D. vitamin K I. meat II. sunflower oil III. green leafy vegetables IV. carrots

Accepted Answer

A-IV, B-I, C-II, D-III. Carrots are rich in β-carotene, the precursor of vitamin A. Vitamin B₁₂ is essentially absent from plants and comes from animal sources such as meat. Vitamin E is a fat-soluble antioxidant found in vegetable oils like sunflower oil. Vitamin K takes its name from Koagulation and comes from green leafy vegetables.

Answer

A-II, B-III, C-IV, D-I

Answer

A-IV, B-II, C-I, D-III

Answer

A-III, B-I, C-IV, D-II

Question 3

Match List-I with List-II and choose the correct answer from the options given below. List-I (Name of vitamin): A. Vitamin B₁₂ B. Vitamin D C. Vitamin B₂ D. Vitamin B₆ List-II (Deficiency disease): I. Cheilosis II. Convulsions III. Rickets IV. Pernicious anaemia

Accepted Answer

A-IV, B-III, C-I, D-II. Vitamin B₁₂ (cyanocobalamin) is required for red blood cell maturation, and its deficiency causes pernicious anaemia. Vitamin D controls calcium and phosphate deposition in bone, so its deficiency causes rickets in children. Vitamin B₂ (riboflavin) deficiency shows up as cheilosis, the cracking at the corners of the mouth. Vitamin B₆ (pyridoxine) deficiency causes convulsions. That gives A-IV, B-III, C-I, D-II.

Answer

A-I, B-III, C-II, D-IV

Answer

A-II, B-III, C-I, D-IV

Answer

A-IV, B-III, C-II, D-I

Q1.The correct statement about peptides and proteins is

Q2.Match the vitamins in List I with their sources in List II. Choose the correct answer from the options given below.

Q3.Match List-I with List-II and choose the correct answer from the options given below.