Active Transport Pump -

In biology, a "pump" is a transmembrane protein that actively moves ions or molecules across a cell membrane.

Moving Uphill: Understanding Active Transport Pumps Active transport is a fundamental biological process that allows cells to move substances against their natural flow. Unlike passive transport, which relies on simple diffusion, active transport requires a specialized mechanism—the —to move molecules from areas of low concentration to areas of high concentration . How Active Transport Pumps Work

| Pump Type | Direction | Energy Source | Main Function | | :--- | :--- | :--- | :--- | | | 3 Na+ out / 2 K+ in | Direct ATP | Nerve impulses, muscle tone | | Proton Pump | H+ out (or into organelle) | Direct ATP | pH regulation, stomach acid | | Calcium Pump | Ca2+ into storage | Direct ATP | Muscle relaxation | | Co-Transport | Varies (Symport/Antiport) | Gradient (Indirect) | Nutrient absorption (e.g., glucose) |

This relies on the concentration gradient created by a primary pump (like the Sodium-Potassium pump).