The carbon dioxide acceptor in Calvin cycle/ `C_(3)`- plants is

Options

A. PEP
B. RuBP
C. PGA
D. NADP

Answer

**Step-by-Step Solution:**

1. **Understanding the Calvin Cycle**: The Calvin cycle, also known as the dark reaction or light-independent reaction, is a crucial part of photosynthesis that takes place in the chloroplasts of plant cells. It involves the fixation of carbon dioxide (CO₂) into organic molecules.

2. **Identifying the Carbon Dioxide Acceptor**: In the Calvin cycle, the first step involves the fixation of CO₂. The molecule that accepts CO₂ is essential for the cycle to proceed.

3. **Recognizing the Key Molecule**: The carbon dioxide acceptor in the Calvin cycle is a specific type of sugar. It is a 5-carbon ketose sugar known as ribulose bisphosphate (RuBP).

4. **Chemical Name**: The full chemical name of RuBP is ribulose 1,5-diphosphate. This molecule plays a critical role in the initial step of the Calvin cycle.

5. **Enzyme Involvement**: The enzyme that catalyzes the reaction between CO₂ and RuBP is called Rubisco, which stands for ribulose bisphosphate carboxylase/oxygenase. This enzyme facilitates the carboxylation of RuBP, allowing the cycle to continue.

6. **Conclusion**: Therefore, the carbon dioxide acceptor in the Calvin cycle of C3 plants is ribulose bisphosphate (RuBP).

**Final Answer**: The carbon dioxide acceptor in the Calvin cycle/C3 plants is ribulose bisphosphate (RuBP).

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