The first carbohydrate, a 3C sugar produced during photosynthesis is

Options

A. oxaloacetic acid
B. RuBP
C. PGA
D. PGAL

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants synthesize food using sunlight, carbon dioxide (CO2), and water. This process primarily occurs in the chloroplasts of plant cells.

2. **Identifying the Cycle**: The question specifically asks about the first carbohydrate produced during photosynthesis. This occurs in the Calvin cycle, which is also known as the C3 cycle because it produces a 3-carbon compound.

3. **First Carbohydrate Produced**: During the Calvin cycle, the first carbohydrate produced is phosphoglyceric acid (PGA). This is a 3-carbon sugar that is formed when CO2 is fixed.

4. **Enzyme Involvement**: The reaction that leads to the formation of PGA is catalyzed by an enzyme called ribulose bisphosphate carboxylase (commonly referred to as Rubisco). This enzyme facilitates the fixation of CO2 to ribulose bisphosphate (RuBP).

5. **Process Overview**: The Calvin cycle consists of three main stages:
- **CO2 Fixation**: CO2 is fixed to RuBP by Rubisco, resulting in the formation of PGA.
- **Reduction**: PGA is then converted into glyceraldehyde-3-phosphate (G3P) through a series of reactions.
- **Regeneration**: Some G3P molecules are used to regenerate RuBP, allowing the cycle to continue.

6. **Conclusion**: Therefore, the first carbohydrate, a 3-carbon sugar produced during photosynthesis, is phosphoglyceric acid (PGA).

**Final Answer**: The first carbohydrate, a 3C sugar produced during photosynthesis is phosphoglyceric acid (PGA).

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