In a CAM plant the concentration of organic acid

Options

A. Decreases during night
B. Increases during day
C. Increases during night
D. Both A and B.

Answer

**Step-by-Step Solution:**

1. **Understanding CAM Plants:**
- CAM (Crassulacean Acid Metabolism) plants are specialized plants that have adapted to arid environments. They are known for their unique photosynthetic process, which allows them to conserve water.

2. **Stomatal Behavior:**
- In CAM plants, the stomata (tiny openings on the leaves) open during the night and close during the day. This is in contrast to most plants, which open their stomata during the day.

3. **Carbon Dioxide Uptake:**
- At night, when the stomata are open, carbon dioxide (CO2) enters the plant. This CO2 is then fixed into a 4-carbon compound called oxaloacetate by the enzyme phosphoenolpyruvate (PEP) carboxylase.

4. **Formation of Organic Acids:**
- The oxaloacetate is subsequently converted into malate and other organic acids. Therefore, during the night, the concentration of these organic acids increases as they accumulate.

5. **Daytime Processes:**
- During the day, the stomata are closed to minimize water loss. The stored organic acids are then broken down to release CO2, which is used in the Calvin cycle for photosynthesis.

6. **Conclusion:**
- Based on the above processes, the concentration of organic acids in CAM plants increases during the night when they are formed and decreases during the day when they are utilized for photosynthesis. Thus, the correct answer to the question is that the concentration of organic acids increases during the night.

**Final Answer:**
- The concentration of organic acids in CAM plants increases during the night.

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