Question

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Isoelectric focusing (IEF) is a highly sensitive analytical technique and is particularly useful for studying micro-heterogeneity in a protein.
Reason (R): A protein may show a single band on SDS gel, but may show three bands on an IEF gel. The method is particularly useful for separating isoenzymes, which are same forms of the different enzyme.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• B. Both (A) and (R) are correct but (R) is NOT the correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Hint:

IEF separates by charge (pI); isoenzymes are different forms of the SAME enzyme, so R's wording is wrong.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:

• We must judge Assertion A and Reason R about isoelectric focusing (IEF).

Step 2: Detailed Explanation:

• Assertion A is correct: IEF separates proteins by isoelectric point and is very sensitive to small charge differences, so it reveals micro-heterogeneity.

• In Reason R the first sentence (one band on SDS gel, three on IEF) is true, but the last part is wrong: isoenzymes are different molecular forms of the same enzyme, not the same forms of different enzymes.

• Hence A is correct but R is not correct.

Step 3: Final Answer:
The correct option is (C) (A) is correct but (R) is not correct.