Identify the correct sequence of enzymes given below which participate in regeneration phase of Calvin cycle
1. Ribulose 5-phosphate epimerase
2. Ribulose 5-phosphate kinase
3. Transketolase
4. Triose phosphate isomerase.

Options

A. 4,1,3,2
B. 2,3,1,4
C. 1,2,3,4
D. 3,2,1,4

Answer

To identify the correct sequence of enzymes that participate in the regeneration phase of the Calvin cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Calvin Cycle**: The Calvin cycle consists of three main phases: carboxylation, reduction, and regeneration. The regeneration phase is crucial for the regeneration of ribulose 1,5-bisphosphate (RuBP), which is essential for the continuation of the cycle.

2. **Identifying the Enzymes**: The enzymes listed in the question are:
- Ribulose 5-phosphate epimerase
- Ribulose 5-phosphate kinase
- Transketolase
- Triose phosphate isomerase

3. **Analyzing Each Enzyme's Role**:
- **Triose phosphate isomerase**: This enzyme catalyzes the conversion of 3-phosphoglyceraldehyde (G3P) to dihydroxyacetone phosphate (DHAP). This reaction is part of the regeneration phase.
- **Ribulose 5-phosphate epimerase**: This enzyme converts xylulose 5-phosphate to ribulose 5-phosphate. It is involved in the interconversion of sugar phosphates.
- **Transketolase**: This enzyme catalyzes the transfer of a two-carbon unit from one sugar phosphate to another, playing a role in the conversion of fructose 6-phosphate and glyceraldehyde 3-phosphate to xylulose 5-phosphate and erythrose 4-phosphate.
- **Ribulose 5-phosphate kinase**: This enzyme phosphorylates ribulose 5-phosphate to regenerate ribulose 1,5-bisphosphate (RuBP), which is essential for the Calvin cycle to continue.

4. **Correct Sequence of Enzymes**: Based on their roles in the regeneration phase, the correct sequence of enzymes is:
- **Triose phosphate isomerase** (1st)
- **Ribulose 5-phosphate epimerase** (2nd)
- **Transketolase** (3rd)
- **Ribulose 5-phosphate kinase** (4th)

### Final Answer:
The correct sequence of enzymes participating in the regeneration phase of the Calvin cycle is:
1. Triose phosphate isomerase
2. Ribulose 5-phosphate epimerase
3. Transketolase
4. Ribulose 5-phosphate kinase