Question

Which enzymatic treatment is used for the efficient isolation of protoplasts from plant cells?
A. Pectinase
B. Nitrogenase
C. Cellulase
D. Cellulose synthase
Choose the correct answer from the options given below:

• A. A and D only
• B. A and C only
• C. B and D only
• D. B and C only

Hint:

To isolate a protoplast, you need to dissolve the wall. Think of it as a demolition job: use Cellulase for the "bricks" (cellulose) and Pectinase for the "mortar" (pectin).

Answer 1

The Correct Option is B

Concept: Protoplasts are "naked" plant cells that have had their protective cell walls removed. Since the plant cell wall is a complex structure made primarily of cellulose and pectin, specific enzymes are required to digest these components without harming the living cell inside.

Step 1: Targeting the Middle Lamella (A).
Plant cells are held together by the middle lamella, which is composed mainly of pectin. Pectinase (A) is used to break down this "intercellular glue," allowing the individual cells to separate from the tissue mass.

Step 2: Targeting the Primary Cell Wall (C).
The rigid structural component of the cell wall is cellulose. Cellulase (C) is the enzyme responsible for degrading these cellulose microfibrils. By using a "cocktail" of pectinase and cellulase, the wall is completely dissolved, releasing the spherical protoplast.

Step 3: Eliminating Non-Degrading Enzymes.
Nitrogenase (B) is an enzyme used by certain bacteria to fix atmospheric nitrogen and has nothing to do with cell wall digestion. Cellulose synthase (D) is an enzyme that *builds* cellulose; adding it would be counterproductive to isolation.