Which of the following is not a polymeric substance?

(1) Nucleic acid               

(2) Proteins

(3) Polysaccharides           

(4) Lipids

A non-proteinaceous enzyme is

(1) lysozyme           

(2) ribozyme

(3) ligase               

(4) deoxyribonuclease

Which of the following is the least likely to be involved in stabilising the three-dimensional folding of most proteins?

(1) Hydrogen bonds

(2) Electrostatic interaction

(3) Hydrophobic interaction

(4) Ester bonds

Which of the following describes the graph correctly?

(1) Endothermic reaction with energy A in the presence of enzyme and B in the absence of enzyme

(2) Exothermic reaction with energy A in the presence of enzyme and B in the absence of enzyme

(3) Endothermic reaction with energy A in the absence of enzyme and B in the presence of enzyme

(4) Exothermic reaction with energy A in the absence of enzyme and B in the presence of enzyme

Which one of the following statements is wrong?

(1) Cellulose is a polysachharide

(2) Uracil is a pyrimidine

(3) Glycine is a sulphur containing amino acid

(4) Sucrose is a diasaccharide

A typical fat molecule is made up of

(1) One glycerol and three fatty acid molecules

(2) One glycerol and one fatty acid molecule

(3) Three glycerol and three fatty acid molecules

(4) Three glycerol molecules and one fatty acid molecule

Which one of the following statement is incorrect ?

1. A competitive inhibitor reacts reversibly with the enzyme to form an enzyme-inhibitor.

2. In competitive inhibition the inhibitor molecule is not chemically changed by the

enzyme.

3. The competative inhibitor does not affect the rate of breakdown of the enzyme-

substrate complex.

4. The presence of the competitive inhibitor decreases the k_m of the enzyme for the

substrate.

A phosphoglyceride is always made up of

1. only a saturated fatty acid esterified to a glycerol molecule to which a phosphate group

is also attached

2. only an unsaturated fatty acid esterified to a glycerol molecule to which a phosphate

group is also attached

3. a saturated or unsaturated fatty acid esterified to a glycerol molecule to which a

phosphate group is also attached

4. a saturated or unsaturated fatty acid esterified to a phosphate group, which is also

attached to a glycerol molecule.

The essential chemical components of many coenzymes are

1. Proteins

2. Nucleic acids

3. Carbohydrates

4. Vitamins

Given below is the diagrammatic representation of one of the categories of small

molecular weight organic compounds in the living tissues. Identify the category shown

and the one blank component X in it

Category              Component

1. Cholesterol       Guanin

2. Amino acid       NH₂

3. Nucleotide        Adenine

4. Nucleoside       Uracil