AP BIOLOGY

Detailed explanation-1: -A concentration gradient is the difference in concentration of a substance from one location to another. A molecule diffuses down its concentration gradient by moving from one region of higher concentration to a region of lower concentration.

Detailed explanation-2: -For cell transport, diffusion is the movement of small molecules across the cell membrane. The difference in the concentrations of the molecules in the two areas is called the concentration gradient. The kinetic energy of the molecules results in random motion, causing diffusion.

Detailed explanation-3: -The concentration profile describes the distribution of concentration (e.g., of a specific compound) over a certain distance. The gradient is the slope of one particular point of a concentration profile.

Detailed explanation-4: -A concentration gradient is a just a region of space over which the concentration of a substance changes, and substances will naturally move down their gradients, from an area of higher to an area of lower concentration.