With respect to the sodium-potassium pump, what changes will be observed when one molecule of ATP is used during the process?

Options

A. 3 ions of `Na^(+)` are pumped out and `2K^(+)` are taken in
B. 3 ions of `Na^(+)` are taken in and `2K^(+)` are pumped out
C. 2 ions of `Na^(+)` are thrown out and `3K^(+)` are absorbed
D. 3 ions of `K^(+)` are absorbed, `3Na^(+)` are pumped out

Answer

To solve the question regarding the sodium-potassium pump and the changes observed when one molecule of ATP is used, we can break down the process step-by-step.

### Step-by-Step Solution:

1. **Understanding the Sodium-Potassium Pump**:
- The sodium-potassium pump (Na+/K+ ATPase) is a membrane protein that actively transports sodium (Na+) and potassium (K+) ions across the cell membrane.
- It is crucial for maintaining the electrochemical gradient across the cell membrane, which is essential for various cellular functions, including nerve impulse conduction.

2. **Role of ATP**:
- The pump requires energy to function, which is provided by the hydrolysis of ATP (adenosine triphosphate).
- When ATP is hydrolyzed, it releases energy that powers the transport of ions against their concentration gradients.

3. **Ion Transport Mechanism**:
- For every molecule of ATP hydrolyzed, the sodium-potassium pump typically transports:
- **3 sodium ions (Na+) out of the cell**.
- **2 potassium ions (K+) into the cell**.
- This results in a net loss of one positive charge from the cell, contributing to the negative membrane potential inside the cell.

4. **Changes in Membrane Potential**:
- As sodium ions are pumped out and potassium ions are pumped in, the inside of the cell becomes more negative relative to the outside.
- This change in membrane potential is crucial for the generation of action potentials in nerve cells.

5. **Conclusion**:
- The correct observation when one molecule of ATP is used in the sodium-potassium pump is that **3 sodium ions are pumped out and 2 potassium ions are taken in**.

### Final Answer:
The changes observed when one molecule of ATP is used during the process of the sodium-potassium pump are: **3 sodium ions are pumped out and 2 potassium ions are taken in**.

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