Proteins mainly contain:

(1) C, H, O and N

(2) only C and H

(3) C, H and O

(4) N and H

In the human body, enzymes hydrolyse protein into:

1. a ketonic acid-like CH₃COCOOH

2. a hydroxy acid like CH₃CHOHCOOH

3. dicarboxylic acid-like HOOC—COOH

4. amino acid-like CH₂NH₂COOH

Which statement about protein is wrong?

(1) Proteins occur in all living cells

(2) Proteins invariably contain N, O, C and H

(3) Proteins are synthesized by plant kingdom only

(4) Proteins are also synthesized in laboratory

The main structural feature(s) of protein is/are:

1. The ester linkage

2. The ether linkage

3. The peptide linkage

4. All of these

Proteins give ?

(1) a violet colour with alkaline CuSO₄ solution

(2) form a purple colour on boiling with dilute ninhydrin solution

(3) yellow colour on boiling with HNO₃

(4) all of the above

Which of the following is proteolytic enzyme?

(1) Insulin

(2) Diastase

(3) Pepsin

(4) Adenine

Keratin, a structural protein is present in:

1. hair

2. skin

3. wool

4. All of the above

Blood protein is:

1. Albumin

2. Haemoglobin

3. Both (1) and (2)

4. None of the above

The destruction of the biological nature and activity of proteins by heat or chemical agent is called :-

Enzyme trypsin converts:

1. amino acids into proteins

2. glucose into glycogens

3. starch into sugar

4. proteins into amino acids