PS consists of -

Options

A. only antenna molecule
B. only reaction centre
C. both antenna molecule and reaction centre
D. only LHC

Answer

**Step-by-Step Text Solution:**

1. **Understanding Photosystems**: Photosystems are essential components in the process of photosynthesis, primarily found in the thylakoid membranes of chloroplasts. There are two main types: Photosystem I (PSI) and Photosystem II (PSII).

2. **Components of Photosystems**: Each photosystem consists of two closely linked components:
- **Antenna Complex**: This is made up of hundreds of pigment molecules (like chlorophyll) that capture light energy (photons) and transfer this energy to the reaction center.
- **Reaction Center**: This is where the light energy is converted into chemical energy. The reaction center contains chlorophyll a molecules that are responsible for the primary photochemical reaction.

3. **Specifics of the Reaction Centers**:
- In Photosystem I (PSI), the reaction center is designated as P700, which means it has a peak absorption at 700 nm.
- In Photosystem II (PSII), the reaction center is designated as P680, with a peak absorption at 680 nm.

4. **Conclusion**: Therefore, a photosystem consists of both the antenna complex and the reaction center.

**Final Answer**: Photosystem consists of both the antenna molecule and the reaction center.

---