Question

Assertion : The protein part of the enzyme is called apoenzyme and non-protein part of the enzyme is called co-factor.
Reason : Zinc is a co-factor for the proteolytic enzyme carboxypeptidase.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

Conjugate enzyme is an enzyme which is formed of two parts- a protein part called apoenzyme (e.g., flavoprotein) and a non-protein part named co-factor. The complete conjugate enzyme, consisting of an apoenzyme and a co-factor, is called holoenzyme. $Co$-factor is small, heat stable and dialysable part of conjugate enzyme. It may be inorganic or organic in nature. Organic co-factors are of two types, coenzymes and prosthetic groups. Inorganic co-factors include ions of a variety of minerals e.g., calcium, iron, copper, zinc, magnesium, manganese, potassium, nickel, molybdenum, selenium, cobalt. They usually function as activators. Zinc is required for carboxypeptidase $NA{D}^{+}$ and $NAD{P}^{+}$ activity.