Question

Arrange the following electron acceptors of Z-scheme of photosynthesis based on the movement of electron from P680 onwards.

(A) Iron-Sulphur Proteins
(B) Ferrodoxin
(C) Plastocyanin
(D) Plastoquinones
Choose the correct answer from the options given below:

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

Hint:

In the Z-scheme, electrons flow from P680 to plastoquinones, plastocyanin, iron-sulphur proteins, and finally to ferrodoxin.

Answer 1

The Correct Option is D

Step 1: Understanding the Z-scheme of photosynthesis.
The Z-scheme is a representation of the electron flow in photosynthesis. Electrons are excited in P680 (Photosystem II) and passed along a series of electron acceptors: \[ P680 \rightarrow \text{Plastoquinones} \rightarrow \text{Plastocyanin} \rightarrow \text{Iron-Sulphur Proteins} \rightarrow \text{Ferrodoxin} \] Step 2: Analyze the order.
- Plastoquinones (D) are the first electron acceptors after P680.
- Plastocyanin (C) accepts electrons next.
- Iron-Sulphur Proteins (A) are part of the electron transport chain after Plastocyanin.
- Ferrodoxin (B) is the final electron acceptor in the process.
Step 3: Conclusion.
The correct order based on electron movement is: \[ \text{Plastoquinones} \rightarrow \text{Plastocyanin} \rightarrow \text{Iron-Sulphur Proteins} \rightarrow \text{Ferrodoxin} \]
Final Answer: \[ \boxed{\text{(D), (C), (A), (B)}} \]