Which of the following elements are essential for the photolysis of water ?

Options

A. Ca and Cl
B. Mn and Cl
C. Zn and I
D. Cu and Fe

Answer

**Step-by-Step Solution:**

1. **Understanding Photolysis of Water**: Photolysis of water is a process that occurs during photosynthesis, specifically in the light-dependent reactions. It involves the splitting of water molecules (H2O) into hydrogen ions (H+), electrons (e-), and oxygen gas (O2).

2. **Location of Photolysis**: This process takes place in the chloroplasts of plant cells, particularly within the thylakoid membranes. The thylakoid membranes contain chlorophyll and other pigments that capture light energy.

3. **Chemical Reaction**: The general equation for the photolysis of water can be summarized as:
\[ 2H_2O \rightarrow 4H^+ + 4e^- + O_2 \]
Here, water is split to produce hydrogen ions, electrons, and oxygen.

4. **Requirements for Photolysis**: For the photolysis of water to occur, several factors are necessary:
- Light energy (which is captured by chlorophyll)
- Enzymes that facilitate the reaction

5. **Essential Elements**: The activation of the enzymes involved in the photolysis of water requires specific elements. The two key elements that are essential for this process are:
- **Manganese (Mn)**: This element plays a crucial role in the water-splitting complex.
- **Chlorine (Cl)**: This element is also involved in the enzymatic reactions necessary for photolysis.

6. **Conclusion**: Therefore, the elements essential for the photolysis of water are manganese and chlorine.

**Final Answer**: Manganese and Chlorine are essential for the photolysis of water.

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