Which of the following pumps can you find in the plasma membrane?

• A. Calcium pump
• B. Chloride pump
• C. Proton pump
• D. Sodium-potassium pump

Answer: (D)

Verified step by step guidance

1. Understand the role of pumps in the plasma membrane: Pumps are proteins that actively transport ions across the plasma membrane against their concentration gradient using energy, usually in the form of ATP.
2. Identify the common types of ion pumps found in the plasma membrane: The most well-known pump is the sodium-potassium pump, which is crucial for maintaining the electrochemical gradient across the cell membrane.
3. Review the function of the sodium-potassium pump: This pump moves three sodium ions out of the cell and two potassium ions into the cell, which is essential for various cellular processes, including nerve impulse transmission and muscle contraction.
4. Consider the other pumps listed: While calcium, chloride, and proton pumps exist, they are not as universally present in the plasma membrane as the sodium-potassium pump. Calcium pumps are often found in the sarcoplasmic reticulum, and proton pumps are more common in organelles like lysosomes and mitochondria.
5. Conclude that the sodium-potassium pump is the most prevalent and essential pump found in the plasma membrane, making it the correct answer to the problem.