movement of substances revision

What is diffusion

Diffusion is the movement of particles from an area of high concentration to an area of low concentration.

What factors affect diffusion

• Distance to travel

• Temperature

• Concentration gradient

• Surface area

What is osmosis

Osmosis is the movement of water particles from an area of high concentration to an area of low concentration, across a partially permeable membrane.

What factors affect the rate of osmosis

• Water potential gradient

• Surface area

• Temperature

• Membrane thickness

What is active transport

Active transport is the movement of particles from an area of low concentration to an area of high concentration. It requires energy from ATP.

What factors affect the rate of active transport

• Surface area of the cell membrane

• The number of carrier proteins in the cell membrane