Question

Of the following statements about enzymes, which ones are true?
(i) enzymes lack in nucleophilic groups
(ii) enzymes are highly specific both in binding chiral substrates and in catalyzing their reactions
(iii) enzymes catalyze chemical reactions by lowering the activation energy
(iv) pepsin in proteolytic enzyme

• A. (i)
• B. (i) and (iv)
• C. (i) and (iii)
• D. (ii), (iii) and (iv)

Answer 1

Answer: (C)

(i) and (iii)

As properties of an enzyme are:

(i) They don't initiate the catalysis by accelerating the rate of catalysis by lowering the activation energy.

(ii) A particular enzyme attacks on a particular substrate (it fits like a key in the lock).

(iii) Any enzyme which breaks the long chain molecules of proteins into shorter fragments (peptides) and eventually into their components, amino acids called proteolytic enzyme.

Pepsin is such an example.