If `36CO_2` molecules are fixed in `C_3` plant what will be :

Options

A. The number of G - 3P and
B. Erythrose - 4- Phosphate formed during the dark reaction
C. a = 144 , b =24
D. a = 72, b = 12

Answer

To solve the problem of how many G3P (Glyceraldehyde-3-phosphate) and erythrose 4-phosphate (E4P) molecules are formed when 36 CO2 molecules are fixed in a C3 plant, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Calvin Cycle**:
- The Calvin cycle is the process by which CO2 is fixed in plants. For every 3 CO2 molecules that enter the cycle, 6 G3P molecules are produced.

2. **Calculate G3P Production**:
- Since 3 CO2 molecules yield 6 G3P molecules, we can set up a proportion to find out how many G3P molecules are produced from 36 CO2 molecules.
- The relationship can be expressed as:
\[ \text{If } 3 \text{ CO2} \rightarrow 6 \text{ G3P} \]
\[ \text{Then } 36 \text{ CO2} \rightarrow X \text{ G3P} \]
- To find X, we can use cross-multiplication:
\[ X = \left(\frac{6 \text{ G3P}}{3 \text{ CO2}}\right) \times 36 \text{ CO2} = \frac{6 \times 36}{3} = 72 \text{ G3P} \]

3. **Calculate Erythrose 4-Phosphate (E4P) Production**:
- It is known that for every 3 CO2 molecules fixed, 1 E4P molecule is produced.
- Using the same proportion:
\[ \text{If } 3 \text{ CO2} \rightarrow 1 \text{ E4P} \]
\[ \text{Then } 36 \text{ CO2} \rightarrow Y \text{ E4P} \]
- Again, using cross-multiplication:
\[ Y = \left(\frac{1 \text{ E4P}}{3 \text{ CO2}}\right) \times 36 \text{ CO2} = \frac{36}{3} = 12 \text{ E4P} \]

4. **Final Results**:
- From the calculations, we find that:
- The number of G3P molecules formed is **72**.
- The number of E4P molecules formed is **12**.

### Summary of Results:
- **G3P**: 72
- **E4P**: 12