Question

Enzymes with cofactors are called __(i)__. Based on the structure and function, the cofactors are grouped as__(ii)__, __(iii)__ and __(iv)__.

• A. (i) Metal ions (ii) Apoenzymes (iii) Prosthetic groups (iv) Coenzymes.
• B. (i) Holoenzymes (ii) Prosthetic groups (iii) Coenzymes (iv) Metal ions.
• C. (i) Prosthetic groups (ii) Coenzymes (iii) Metal ions (iv) Apoenzymes.
• D. (i) Coenzyme (ii) Metal ions (iii) Apoenzymes (iii) Prosthetic groups.

Answer 1

The correct option is B

(i) Holoenzymes (ii) Prosthetic groups (iii) Coenzymes (iv) Metal ions.

Enzymes with co-factors are called (i). Holoenzymes, The cofactors can be simple inorganic metallic ions or complex organic compounds like vitamins or its derivatives. They are broadly grouped as:

(ii). Prosthetic groups are cofactors which are tightly bound or even covalently bound,to the enzyme. Eg : the Heme group in hemoglobin

(iii). Coenzymes are metallic or complex organic or organometallic compounds with loose linkages to the main enzyme.

(iv). For some enzyme some metallic ions act as cofactors.