Question

Explain active transport of substances across cell membranes.

Answer 1

In primary active transport, the proteins involved are pumps that normally use chemical energy in the form of ATP. ... These proteins have receptors that bind to specific molecules (e.g., glucose) andtransport them across the cell membrane.

Answer 2

Active transport: moving against a gradient. To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.