Among the following , identical the substrate required for the only oxidative reaction that occurs in the process of glucolysis .

Options

A. 3- Phosphoglyceric acid
B. Glyceraldehyde - 3-phosphate
C. Fructose 6-phosphate
D. Glucose 6-phosphate

Answer

To solve the question regarding the substrate required for the only oxidative reaction that occurs in glycolysis, we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding Glycolysis**: Glycolysis is a metabolic pathway that converts glucose into pyruvate, producing ATP and NADH in the process. It consists of several steps, including phosphorylation, isomerization, and oxidation.

2. **Identifying the Oxidative Reaction**: In glycolysis, the only oxidative reaction occurs when glyceraldehyde 3-phosphate (G3P) is oxidized. This reaction is catalyzed by the enzyme glyceraldehyde 3-phosphate dehydrogenase.

3. **Substrate for the Oxidative Reaction**: The substrate for this oxidative reaction is glyceraldehyde 3-phosphate (G3P). During this reaction, G3P is oxidized, and NAD+ is reduced to NADH + H+.

4. **Other Options**:
- **Glucose 6-phosphate** is formed from glucose and is not involved in the oxidative reaction.
- **Fructose 6-phosphate** is a product of isomerization and does not participate in the oxidation.
- **1,3-bisphosphoglycerate** is a product of the oxidation of G3P and not the substrate.

5. **Conclusion**: Therefore, the substrate required for the only oxidative reaction that occurs in glycolysis is glyceraldehyde 3-phosphate.

### Final Answer:
**Glyceraldehyde 3-phosphate (G3P)**