Final answer:
Proton pumps are protein complexes that transport protons across cell membranes against their concentration gradient using ATP energy.
Step-by-step explanation:
Proton pumps are protein complexes that transport protons (H+) across cell membranes against their concentration gradient. They use energy from ATP (adenosine triphosphate) to actively move protons from an area of low concentration to an area of high concentration.
For example, the sodium-potassium pump is a type of proton pump that moves sodium ions out of the cell and potassium ions into the cell. This process requires ATP and carrier proteins to change shape and transport the ions across the membrane.
Overall, proton pumps play a vital role in numerous cellular processes, including maintaining pH balance, generating ATP, and regulating ion concentrations.