diffusion

• diffusion is the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration
• urea is a waste product produced inside the cell. it is diffused out of the cell into the blood plasma and is excreted by the kidneys
• the difference in concentrations is called the concentration gradient
• the greater the concentration gradient the faster diffusion takes place
• the higher the temperature the greater the rate of diffusion because the particles have more kinetic energy and are moving faster
• the larger the surface area of the cell membrane the greater the rate of diffusion because more particles can pass through at once
• diffusion happens in both solutions and gases because the particles in these substances are free to move around