Question

comparing the calcium and sodium-potassium pumps
which statement describes a similarity between the calcium pump and the sodium-potassium pump?
both pumps move substances from high concentration to low concentration.
both pumps only move substances into cells.
both pumps require no energy to function.
both pumps use proteins to transport substances across the cell membrane.

Explanation:

The calcium pump and sodium-potassium pump are both active transport mechanisms. Active transport uses protein carriers to move substances across cell membranes, often against concentration gradients (requiring energy). The correct statement identifies this shared reliance on proteins for transport.

Answer:

Both pumps use proteins to transport substances across the cell membrane.