What is active transport through the cell surface membrane?

Active transport through the cell surface membrane is a process that requires energy to move substances against their concentration gradient. This means that molecules are transported from an area of lower concentration to an area of higher concentration, which is contrary to the natural tendency of substances to move toward equilibrium.

The energy for active transport typically comes from ATP (adenosine triphosphate), which is utilized by specific protein pumps embedded in the cell membrane. These pumps facilitate the movement of ions or molecules that are critical for various cellular functions, such as maintaining ion balance, nutrient uptake, and waste removal.

In contrast, transport that does not require energy, passive diffusion, or osmotic pressure involves the movement of molecules along their concentration gradient without the input of energy. These processes are essential in cell function but are fundamentally different from active transport because they do not involve the energy-dependent mechanisms that characterize active transport.