The photochemical phase of photosynthesis includes (a) Water splitting (b) Light absorption (c) Oxygen release (d) Synthesis of NADPH (e) Synthesis of starch

Options

A. Only (a) & (b)
B. (b), (c) & (e)
C. (c), (d) & (e)
D. All except (e)

Answer

To answer the question regarding the components of the photochemical phase of photosynthesis, we need to analyze each option provided in the question:

1. **Water Splitting (Photolysis)**: This process occurs during the photochemical phase where water molecules are split into hydrogen ions (H⁺) and oxygen (O₂). This is a crucial step in photosynthesis as it provides the electrons needed for the light reactions.

2. **Light Absorption**: The photochemical phase involves the absorption of light by chlorophyll and other pigments in the chloroplasts. This light energy is essential for driving the reactions that occur during this phase.

3. **Oxygen Release**: As a result of water splitting, oxygen is released as a by-product during the photochemical phase. This is an important aspect of photosynthesis, contributing to the oxygen supply in the atmosphere.

4. **Synthesis of NADPH**: During the photochemical phase, NADP⁺ is reduced to NADPH, which is used in the subsequent stages of photosynthesis (Calvin cycle) for the synthesis of carbohydrates.

5. **Synthesis of Starch**: This process does not occur during the photochemical phase. Instead, starch synthesis happens during the Calvin cycle, where the products of the light reactions (ATP and NADPH) are used to convert carbon dioxide into glucose, which can then be stored as starch.

Based on this analysis, the correct components of the photochemical phase of photosynthesis include options A (Water splitting), B (Light absorption), C (Oxygen release), and D (Synthesis of NADPH). However, option E (Synthesis of starch) does not belong to the photochemical phase.

**Final Answer**: The correct answer is "all except E" (A, B, C, D).