Question

Select the INCORRECT statements.

i. The rate of formation of \(\mathrm{H}_2 \mathrm{CO}_3\) is slower in RBCs and faster in plasma.

ii. Dissociation of \(\mathrm{H}_2 \mathrm{CO}_3\) into \(\mathrm{H}^{+}\)and \(\mathrm{HCO}_3^{-}\) takes place due to carbonic anhydrase.

iii. The carbonic anhydrase is present in leucocytes,

iv. The prosthetic group of carbonic anhydrase is Mn .

Select the correct option.

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

Hint:

Carbonic anhydrase is rich in RBCs, contains zinc and speeds up H2CO3 formation.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
\(\text{CO}_2 + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3 \rightleftharpoons \text{H}^{+} + \text{HCO}_3^{-}\) is catalysed by carbonic anhydrase.

Step 2: Check each statement
(i) incorrect: formation is faster in RBCs (high enzyme level) and slower in plasma.
(ii) accepted as correct: the enzyme facilitates the reaction in both directions.
(iii) incorrect: the enzyme is abundant in RBCs, not leucocytes.
(iv) incorrect: the prosthetic group is zinc, not manganese.

Step 3: Compare the options
Incorrect statements are i, iii and iv.

Final Answer:
Statements i, iii and iv are incorrect. \[ \boxed{\text{(C) }\text{i, iii and iv only}} \]