Active Transport — In Plasma Membrane Repack

The sodium-potassium pump is a classic example of primary active transport. This pump uses ATP to transport sodium ions out of the cell and potassium ions into the cell. The pump works by:

, also known as co-transport, is more indirect and ingenious. It does not use ATP directly. Instead, it harvests the potential energy stored in the electrochemical gradient of one solute (typically Na+ or H+)—a gradient that was itself established by primary active transport. By coupling the downhill movement of this "driver" ion to the uphill movement of a target molecule, a single transport protein can perform two tasks simultaneously. There are two forms of secondary active transport: symport (or co-transport), where the driver ion and the target molecule move in the same direction across the membrane, and antiport (or exchange), where they move in opposite directions. active transport in plasma membrane

-ATPase): The most well-known example, this pump moves three sodium ions out of the cell and two potassium ions into the cell. It is essential for maintaining the electrochemical gradient required for nerve impulse transmission and muscle contraction. These move hydrogen ions ( H+cap H raised to the positive power The sodium-potassium pump is a classic example of

Na+/K+cap N a raised to the positive power / cap K raised to the positive power It does not use ATP directly