For yielding one molecule of glucose the Calvin cycle turns

Options

A. two times
B. four times
C. six times
D. eight times

Answer

To determine how many times the Calvin cycle turns to yield one molecule of glucose, we can follow these steps:

### Step 1: Understand the Composition of Glucose
Glucose (C₆H₁₂O₆) is a simple sugar that contains six carbon atoms.

**Hint:** Recall the molecular formula of glucose to identify the number of carbon atoms present.

### Step 2: Know the Function of the Calvin Cycle
The Calvin cycle is a series of biochemical reactions that occur in the stroma of chloroplasts in photosynthetic organisms. It is responsible for carbon fixation, where carbon dioxide (CO₂) is converted into organic compounds.

**Hint:** Remember that the Calvin cycle is essential for converting CO₂ into carbohydrates.

### Step 3: Determine the Carbon Fixation Rate
Each turn of the Calvin cycle fixes one carbon atom from CO₂. Therefore, to produce one molecule of glucose, which contains six carbon atoms, the cycle must turn multiple times.

**Hint:** Think about how many carbon atoms need to be fixed to create glucose.

### Step 4: Calculate the Number of Turns Required
Since each turn of the Calvin cycle fixes one carbon atom, to fix six carbon atoms (as in glucose), the Calvin cycle must turn six times.

**Hint:** Use simple multiplication to relate the number of carbon atoms in glucose to the number of cycles needed.

### Step 5: Conclusion
Thus, to yield one molecule of glucose, the Calvin cycle turns **six times**.

**Final Answer:** The Calvin cycle turns 6 times to yield one molecule of glucose.

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