The primary receptor of `CO_(2)` in photosynthesis is

Options

A. Phosphoric acid
B. Ribulose phosphate
C. Glucose
D. Ribulose 1,5-bisphosphate

Answer

To answer the question about the primary receptor of CO2 in photosynthesis, we can follow these steps:

### Step 1: Understand the context of photosynthesis
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen.

### Step 2: Identify the role of CO2 in photosynthesis
CO2 is a critical component in the photosynthetic process, as it is fixed into organic molecules during the Calvin cycle.

### Step 3: Determine the primary receptor of CO2
In the Calvin cycle, the primary receptor of CO2 is a molecule that captures CO2 to initiate the process of carbon fixation.

### Step 4: Analyze the options provided
The options given are:
1. Phosphoric acid
2. Ribulose phosphate
3. Glucose
4. Ribulose 1,5-bisphosphate

### Step 5: Identify the correct answer
Among the options, ribulose 1,5-bisphosphate (RuBP) is known to be the primary receptor of CO2. It reacts with CO2 in the presence of the enzyme RuBisCO to form two molecules of 3-phosphoglycerate (3-PGA), which is the first stable product of the Calvin cycle.

### Conclusion
The primary receptor of CO2 in photosynthesis is **ribulose 1,5-bisphosphate (RuBP)**.

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