AP BIOLOGY

Detailed explanation-1: -Passive transport is a naturally occurring phenomenon and does not require the cell to expend energy to accomplish the movement. In passive transport, substances move from an area of higher concentration to an area of lower concentration in a process called diffusion.

Detailed explanation-2: -Diffusion is a passive process of transport. A single substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. You are familiar with diffusion of substances through the air.

Detailed explanation-3: -Diffusion is a passive mode of transportation. Passive transport does not require energy. A single substance moves from a high concentration area to a low concentration area until the concentration is uniform throughout the space.

Detailed explanation-4: -Facilitated diffusion does not require high energy molecules such as ATP. This type of diffusion uses channel proteins and carrier proteins to transport molecules across the plasma membrane. Facilitated diffusion involves the movement of molecules from areas of higher concentration to areas of lower concentration.

Detailed explanation-5: -area with lower concentration. The difference between the concentrations is called the “concentration gradient”. Diffusion goes down the gradient until an equilibrium is reached.