Ribulose bisphosphate carboxylase oxygenase ( RuBisCO) enzyme catalyzses the reaction between

Options

A. Oxaloacetic acid and acetyl CoA
B. `CO_2` and ribulose 1,5 bisphosphate
C. Ribulose bisphosphate and phosphoglyceraldehyde
D. PGA and dihydroxyacetone phosphate

Answer

To solve the question regarding the reaction catalyzed by the enzyme Ribulose bisphosphate carboxylase oxygenase (RuBisCO), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding RuBisCO**: RuBisCO is an enzyme that plays a crucial role in the Calvin Cycle, which is part of photosynthesis. It catalyzes the first major step of carbon fixation.

2. **Identify the Substrates**: The primary substrates for the RuBisCO enzyme are ribulose-1,5-bisphosphate (RuBP) and carbon dioxide (CO2).

3. **Reaction Catalyzed**: The RuBisCO enzyme catalyzes the reaction between ribulose-1,5-bisphosphate and carbon dioxide to produce 3-phosphoglycerate (3-PGA). This reaction is known as carboxylation.

4. **Elimination of Incorrect Options**:
- The first option mentions oxaloacetic acid and acetyl-CoA, which are related to the Krebs cycle, not the Calvin cycle.
- The third option mentions ribulose bisphosphate and phosphoglyceraldehyde, which are not directly the substrates for RuBisCO.
- The fourth option mentions PGA and dihydroxyacetone phosphate, which are products of the Calvin cycle but not the substrates for RuBisCO.

5. **Correct Answer**: The correct reaction catalyzed by RuBisCO is between carbon dioxide (CO2) and ribulose-1,5-bisphosphate (RuBP), leading to the formation of 3-phosphoglycerate (3-PGA).

### Final Answer:
RuBisCO catalyzes the reaction between carbon dioxide (CO2) and ribulose-1,5-bisphosphate (RuBP).

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