Which one of the following is the product of the dark reaction of photosynthesis?

Options

A. `CO_(2)`
B. ATP
C. Pyruvic acid
D. Phosphoglyceraldehyde

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which plants convert light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.

2. **Phases of Photosynthesis**: Photosynthesis occurs in two main phases:
- **Light Reactions**: These occur in the thylakoid membranes of the chloroplasts and require sunlight. They produce ATP and NADPH.
- **Dark Reactions (Calvin Cycle)**: These occur in the stroma of the chloroplasts and do not require light directly. They utilize the ATP and NADPH produced in the light reactions to fix carbon dioxide into organic compounds.

3. **Dark Reactions**: The dark reactions involve a series of assimilatory reactions aimed at fixing carbon dioxide into organic compounds. The main enzyme involved in this process is RuBisCO, which catalyzes the reaction between carbon dioxide and ribulose bisphosphate (RuBP).

4. **Formation of Products**: During the dark reactions, carbon dioxide combines with RuBP to form 3-phosphoglycerate (3-PGA). This compound is then converted into glyceraldehyde-3-phosphate (G3P), which can eventually be used to form glucose and other carbohydrates.

5. **Identifying the Product**: The question asks for the product of the dark reaction. The primary product formed during the dark reactions is phosphoglyceraldehyde (G3P), which is also referred to as glyceraldehyde-3-phosphate.

6. **Conclusion**: Therefore, the correct answer to the question is that the product of the dark reaction of photosynthesis is phosphoglyceraldehyde (G3P).

**Final Answer**: The product of the dark reaction of photosynthesis is phosphoglyceraldehyde (G3P).

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