`CO_(2) NADPH_(2)` ATP ratio in CAM plants is

Options

A. 1 2 3
B. 1 2 4
C. 1 2 5
D. 1 2 6

Answer

To find the CO₂, NADPH₂, and ATP ratio in CAM (Crassulacean Acid Metabolism) plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding CAM Plants**:
- CAM plants are adapted to arid environments and have a unique way of fixing CO₂. Their stomata open at night to minimize water loss.

2. **CO₂ Fixation Process**:
- At night, CO₂ enters the plant and is initially fixed by the enzyme phosphoenolpyruvate carboxylase (PEP carboxylase) to form oxaloacetic acid (OAA), which is then converted to malate.

3. **Storage of Malate**:
- The malate produced is stored in vacuoles overnight. During the day, the malate is converted back to pyruvate, releasing CO₂ in the process.

4. **Calvin Cycle**:
- The released CO₂ is then used in the Calvin cycle during the day to produce glucose.

5. **Molecules Required for Glucose Production**:
- To synthesize one glucose molecule, the following are required:
- **6 CO₂ molecules**
- **12 NADPH molecules**
- **30 ATP molecules**

6. **Calculating the Ratio**:
- The ratio of CO₂, NADPH₂, and ATP needed for glucose production can be expressed as:
- CO₂: 6
- NADPH₂: 12
- ATP: 30
- To simplify this ratio, we divide each component by the smallest number, which is 6:
- CO₂: 6/6 = 1
- NADPH₂: 12/6 = 2
- ATP: 30/6 = 5

7. **Final Ratio**:
- Therefore, the simplified ratio of CO₂ : NADPH₂ : ATP in CAM plants is **1 : 2 : 5**.