3. Diffusion and Osmosis

Diffusion

• the net movement of particles from and area of higher concentration to lower concentration.
• molecules will diffuse both ways, but net movement will be to the lower concentration
• this continues until equilibrium is reached
• concentration gradient= the path from high concentration to lower concentration
• particles diffuse down a concentration gradient
• it's passive- no energy/ATP is required
• this occurs across plasma membranes

Factors affecting the rate of Diffusion

• concentration gradient- the higher it is the higher the rate
• thickness of exchange surface- thinner (shorter distance), the faster the rate
• surface area- larger the surface area, the faster the rate
• temperature- the warmer it is, the faster the rate of diffusion because the partices have more kinetic energy so move faster

Osmosis

• the diffusion of water molecules across…