Transport Mechanisms in Cells cape biology unit 1 j.riley

Diffusion

Movement of small, nonpolar molecules through the lipid bilayer from high concentration to low concentration.

Facilitated Diffusion

Movement of larger or polar molecules through protein channels or carriers in the membrane without energy.

Passive Transport

Movement of substances across a membrane without energy expenditure, driven by concentration gradients.

Active Transport

Movement of substances against their concentration gradient requiring energy (ATP) to occur.

Osmosis

A specialized type of diffusion referring to the movement of water through a selectively permeable membrane.

Phagocytosis

Type of endocytosis involving the engulfing of solid particles by cells.

Pinocytosis

Type of endocytosis involving the engulfing of liquids and small molecules by cells.

Sodium-Potassium Pump

An active transport mechanism that moves sodium ions out and potassium ions into cells to maintain membrane potential.

Exocytosis

Process of releasing substances from the cell by fusing vesicles with the plasma membrane.

Concentration Gradient

The difference in concentration of a substance between two areas, driving passive transport.