Which of these reactions is a multi step process ?

Options

A. Glucose `rarr` Glucose -6- phosphate
B. Fumarate `rarr` Oxaloacetate
C. PEPA `rarr` PA
D. Succinyl CoA `rarr` Succinate

Answer

To determine which of the given reactions is a multi-step process, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the first reaction: Glucose to Glucose 6-Phosphate**
- This reaction is catalyzed by the enzyme hexokinase.
- It is a single-step reaction where glucose is phosphorylated to form glucose 6-phosphate.
- **Conclusion:** This is a one-step reaction.

2. **Identify the second reaction: Fumarate to Oxaloacetate**
- This reaction involves the conversion of fumarate to malate and then malate to oxaloacetate.
- It requires the addition of water (H2O) and involves the reduction of NAD+ to NADH.
- Since this reaction involves multiple steps (fumarate → malate → oxaloacetate), it qualifies as a multi-step process.
- **Conclusion:** This is a multi-step reaction.

3. **Identify the third reaction: Phosphoenolpyruvate (PEP) to Pyruvic Acid (PA)**
- This reaction is catalyzed by the enzyme pyruvate kinase.
- It is a direct conversion of phosphoenolpyruvate to pyruvic acid.
- **Conclusion:** This is a one-step reaction.

4. **Identify the fourth reaction: Succinyl-CoA to Succinate**
- This reaction is catalyzed by the enzyme succinyl-CoA synthetase.
- It is a direct conversion of succinyl-CoA to succinate.
- **Conclusion:** This is also a one-step reaction.

### Final Conclusion:
Among the reactions analyzed, the only multi-step process is the conversion of fumarate to oxaloacetate.

**Answer:** The reaction that is a multi-step process is the conversion of fumarate to oxaloacetate.

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