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

Which of the following is an essential amino acid?

1. Cystine                         

2. Glycine

3. Phenylalanine                 

4. Serine

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 vitamins is a coenzyme for amino acid and fatty acid metabolism?

1. Vitamin B₆               

2. Vitamin B₁₂

3. Vitamin B₁               

4. Vitamin B₂

The inhibition of succinic dehydrogenase by malonate is an example of

1. competitive inhibition

2. non-competitive inhibition

3. allosteric modulation

4. none of the above