Question

During the process of ripening of fruits, the transition of pectic substance occurs in the following order:
(A). Protopectin
(B). Pectin
(C). Pectinic acid
(D). Pectic acid
Choose the most appropriate answer from the options given below:

• A. (A), (B), (C), (D)
• B. (B), (A), (C), (D)
• C. (B), (C), (D), (A)
• D. (C), (B), (D), (A)

Hint:

Remember the progression from hard to mushy: Starts with the large, insoluble \textbf{Protopectin} (unripe). This breaks down into soluble \textbf{Pectin} (ripe), which is then further degraded into \textbf{Pectinic acid} and finally \textbf{Pectic acid} (overripe/mushy).

Answer 1

The Correct Option is A

Step 1: Concept Overview:
Pectic substances, complex carbohydrates, act as a cementing agent in plant cell walls, contributing to fruit firmness. Ripening involves enzymatic breakdown of these substances, causing softening, following a defined biochemical process.
Step 3: Detailed Breakdown:
The correct order of pectic substance transformation during ripening is:
1. (A) Protopectin: The water-insoluble form of pectin in unripe, hard fruits. It's a large polymer bound to cell wall cellulose.
2. (B) Pectin: As ripening begins, protopectinase breaks down protopectin into soluble pectin molecules, initiating softening.
3. (C) Pectinic acid: Further ripening involves pectin methylesterase (PME) removing methyl groups from pectin, forming pectinic acids.
4. (D) Pectic acid: In late ripening/over-ripening, polygalacturonase (PG) breaks down polymer chains, and remaining methyl groups are removed, resulting in pectic acid (polygalacturonic acid) and a soft/mushy texture.
The correct sequence is (A) \(\rightarrow\) (B) \(\rightarrow\) (C) \(\rightarrow\) (D).
Note: The provided multiple-choice options [(A), (C), (B), (D), etc.] do not align with the scientifically accurate sequence. The question's options contain an error.
Step 4: Conclusion:
The correct order of pectic substance transition during fruit ripening is Protopectin \(\rightarrow\) Pectin \(\rightarrow\) Pectinic acid \(\rightarrow\) Pectic acid. Since none of the given options match this, the question is flawed.