In PS-II, first known electron acceptor is

Options

A. Cytochrome
B. Quinone
C. FRS
D. Ferredoxin

Answer

**Step-by-Step Solution:**

1. **Understanding Photosystem II (PS-II):** Photosystem II is a crucial component of the photosynthetic process in plants, algae, and some cyanobacteria. It is involved in the light-dependent reactions of photosynthesis.

2. **Location of PS-II:** PS-II is located in the thylakoid membranes of chloroplasts, where it plays a role in capturing light energy and converting it into chemical energy.

3. **Photolysis of Water:** During the process of photosynthesis, specifically in PS-II, water molecules undergo photolysis. This means that water is split into oxygen, protons, and electrons when exposed to light.

4. **Electron Generation:** The splitting of water generates electrons, which are then transferred to the reaction center of PS-II, known as P680.

5. **First Electron Acceptor:** The first known electron acceptor in PS-II is **plastoquinone** (also referred to as phytoquinone). After the electrons are generated, they are passed on to plastoquinone, which is the initial electron carrier in the electron transport chain.

6. **Subsequent Electron Carriers:** Following plastoquinone, the electrons are transferred to other carriers, including quinone A, quinone B, and then to the cytochrome b6f complex. Finally, they reach Photosystem I (PS-I) at the P700 reaction center.

7. **Energy Molecule Formation:** The process in PS-II ultimately leads to the formation of ATP and NADPH, which are essential energy molecules used in the Calvin cycle (dark reactions) of photosynthesis.

**Final Answer:** The first known electron acceptor in Photosystem II (PS-II) is **plastoquinone**.

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