Why is it that the dark reaction is the rate limiting step in photosynthesis?

Explanation

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis consists of two main stages: light reactions and dark reactions (Calvin cycle). Light reactions occur in the presence of sunlight, while dark reactions can occur in the absence of light.

2. **Defining Dark Reactions**: Dark reactions, also known as the Calvin cycle, take place in the stroma of chloroplasts. They involve the fixation of carbon dioxide (CO2) and the synthesis of glucose using ATP and NADPH produced during light reactions.

3. **Rate Limiting Step**: A rate-limiting step in a biochemical pathway is the slowest step that determines the overall rate of the process. In photosynthesis, the dark reaction is considered the rate-limiting step because it occurs at a slower rate compared to the light reactions.

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