diffusion 1.3.1

• diffusion is the net movement of particles of a gas or solute from an area of high concentration to an area of low concentration (down a concentration gradient)
• the movement of particles when diffusing is always random
• increase of temperature increases the rate of diffusion into the cell
• increase of the concentration gradient increases the rate of diffusion into the cell
• decreasing the amount of substance inside the cell increases the rate of diffusion into the cell
• having lots of infolding of the cell membrane increases the rate of diffusion into the cell
• decreasing the temperature decreases the rate of diffusion into the cell
• decreasing the concentration gradient decreases the rate of diffusion into the cell
• decreasing the amount of substance outside the cell decreases the rate of diffusion into the cell
• adding more water inside the cell increases the rate of diffusion into the cell
• increasing the surface area increases the rate of diffusion into thr cell
• increasing the amount of substance inside the cell decreases the rate of diffusion into the cell
• adding more water outside the cell decreases the rate of diffusion into the cell
• decreasing the surface area decreases the rate of diffusion into the cell
• increasing the amount of substance outside the cell increases the rate of diffusion into the cell
• hotter temperatures give molecules more kinetic energy so they move faster and the rate of diffusion is increased
• more surface area means more particles can enter the cell in the same time period and increases the rate of diffusion
• diffusion relies on the random movement of particles and a bigger difference in concentration gradient means overall more particles will diffuse from higher to lower concentration
• diffusion is very slow and so if the distance is shorter, it will take less time for the substance to diffuse into the cell
• an example of diffusion is the waste product urea from cells diffusing into the blood plasma for excretion in the kidney