Number of H+ that must be transported through ATP synthase or coupling factor (`CF_(0)` -CF1) to form one ATP is

Options

A. one
B. two
C. three
D. four

Answer

To solve the question regarding the number of H+ ions that must be transported through ATP synthase (CF0-CF1) to form one ATP, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding ATP Synthesis**: ATP synthesis in higher plants occurs through a process known as chemiosmosis, which involves the movement of protons (H+) across a membrane.

2. **Identify the Components**: The ATP synthase complex (CF0-CF1) is embedded in the thylakoid membrane of chloroplasts. It consists of two main parts: CF0, which is the proton channel, and CF1, which is responsible for ATP synthesis.

3. **Proton Gradient**: For ATP synthesis to occur, there must be a proton concentration gradient across the membrane. This means that there is a higher concentration of H+ ions on one side of the membrane compared to the other.

4. **Proton Movement**: As protons move from an area of high concentration to low concentration through the ATP synthase complex, they provide the energy needed for the synthesis of ATP from ADP and inorganic phosphate (Pi).

5. **Quantifying H+ Transport**: It is established that for every 3 protons (H+) that pass through the ATP synthase complex, one molecule of ATP is produced.

6. **Conclusion**: Therefore, the number of H+ ions that must be transported through ATP synthase to form one ATP is 3.

### Final Answer:
The number of H+ ions that must be transported through ATP synthase or coupling factor (CF0-CF1) to form one ATP is **3**.