Third, active transport enables itself. As described, the absorption of essential nutrients like glucose and amino acids in the gut, the reabsorption of water and ions in the kidney, and the loading of neurotransmitters into synaptic vesicles all depend on the prior work of primary pumps. In this sense, primary active transport is the battery, and secondary active transport is the device it powers.
Na+/K+cap N a raised to the positive power / cap K raised to the positive power active transport in plasma membrane