Which of the following is the first stable product of c3 cycle ?

Options

A. 1, 5 rubp
B. rubisco
C. oxaloacetic acid
D. phosphoglyceraldehyde

Answer

**Step-by-Step Solution:**

1. **Understanding the C3 Cycle:** The C3 cycle, also known as the Calvin cycle, is a crucial part of photosynthesis that occurs in plants. It is called the C3 cycle because the first stable product formed in this cycle is a three-carbon compound.

2. **Identifying the First Stable Product:** In the C3 cycle, the process begins when a 5-carbon molecule called ribulose bisphosphate (RuBP) combines with carbon dioxide (CO2). This reaction is known as carboxylation.

3. **Role of the Enzyme RuBisCO:** The enzyme responsible for facilitating this reaction is RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase). RuBisCO is the most abundant enzyme on Earth and plays a critical role in the fixation of carbon dioxide.

4. **Formation of 3-PGA:** The carboxylation reaction results in the formation of two molecules of 3-phosphoglycerate (3-PGA), which is a three-carbon compound. This makes 3-PGA the first stable product of the C3 cycle.

5. **Conclusion:** Therefore, the first stable product of the C3 cycle is 3-phosphoglycerate (3-PGA).

**Final Answer:** The first stable product of the C3 cycle is 3-phosphoglycerate (3-PGA).

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