How many PGAL molecules would regenerate 15 RuBP

Options

A. 30
B. 25
C. 15
D. 20

Answer

To solve the question of how many PGAL molecules would regenerate 15 RuBP, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Relationship**: We know that 3 RuBP molecules are regenerated from 5 PGAL molecules. This is a crucial relationship that we will use to find our answer.

2. **Calculate PGAL Required for One RuBP**: To find out how many PGAL molecules are needed for one RuBP, we can set up a ratio:
\[ \text{PGAL per RuBP} = \frac{5 \text{ PGAL}}{3 \text{ RuBP}} = \frac{5}{3} \text{ PGAL per RuBP} \]

3. **Calculate PGAL Required for 15 RuBP**: Now, we need to find out how many PGAL molecules are required to regenerate 15 RuBP. We can multiply the PGAL required for one RuBP by the number of RuBP we want to regenerate:
\[ \text{PGAL for 15 RuBP} = \left(\frac{5}{3} \text{ PGAL per RuBP}\right) \times 15 \text{ RuBP} \]
\[ = \frac{5 \times 15}{3} = \frac{75}{3} = 25 \text{ PGAL} \]

4. **Conclusion**: Therefore, the number of PGAL molecules required to regenerate 15 RuBP is 25.

### Final Answer:
The number of PGAL molecules that would regenerate 15 RuBP is **25**.

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