Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched

with the category mentioned against it?

1. Thymine, Uracil         - Pyrimidines

2. Uracil, Cytosine         - Pyrimidines

3. Guanine, Adenine      - Purines

4. Adenine, Thymine     - Purines

A competive inhibitor of succinic dehydrogenase is

1. malonate                 

2. oxaloacetate

3. $\mathrm{\alpha }$-ketoglutarate       

4. malate

An organic substance bound to an enzyme and essential for its activity is called:

1. coenzyme                   

2. holoenzyme

3. apoenzyme                 

4. isoenzyme

The enzyme amylase belongs to the class

1. hydrolase                       

2. isomerase

3. transferase                     

4. lyases

Cobalt is present in the molecule of

1. vitamin B₆

2. vitamin B₁₂

3. vitamin B₂

4. vitamin B₁

DNA has deoxyribose as the constituent sugar. The position where the sugar lacks oxygen is

1. 1

2. 2

3. 3

4. 4

The linkage that joins two adjacent nucleotides in RNA is

1. phosphate ester                 

2. phosphodiester

3. phosphate anhydride         

4. N-glycoside

Phosphodiester bond is present in

1. ATP

2. ADP

3. cAMP

4. none of these

Heating may cause denaturation of enzyme or protein mainly by damaging its

1. physical configuration

2. chemical structure

3. both physical configuration as well as chemical structure

4. other properties.

Which of the following is incorrect?

1. The hair protein, keratin, is synthesized from the amino acid methionine

2. Phospholipids act as carriers of small non polar molecules across the cell membrane

3. Dietary intake of PUFA decreases the serum cholesterol level in our body

4. Cobalt is a constituent of Vit B₁₂