The first stable product of CAM cycle is

Options

A. Oxalic acid
B. Malic acid
C. Oxalo-acetic acid
D. Pyruvic acid

Answer

**Step-by-Step Solution:**

1. **Understand the CAM Cycle**: The CAM (Crassulacean Acid Metabolism) cycle is a carbon fixation pathway that some plants use to adapt to arid conditions. In this process, plants open their stomata at night to minimize water loss.

2. **Identify the Role of Stomata**: Stomata are small openings on the surface of leaves that allow for gas exchange. In CAM plants, these openings are primarily active at night, allowing CO2 to enter the plant.

3. **Carbon Fixation Process**: During the night, CO2 is fixed into a four-carbon compound. The primary acceptor of CO2 in the CAM pathway is phosphoenolpyruvic acid (PEP).

4. **First Stable Product Formation**: The first stable product formed from the reaction of CO2 with PEP is oxaloacetic acid (OAA). This compound is then converted into malic acid for storage.

5. **Conclusion**: The first stable product of the CAM cycle is oxaloacetic acid.

**Final Answer**: The first stable product of the CAM cycle is **oxaloacetic acid**.

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