Diffusion

• Movement of particles from a high concentration to a low concentration
• Happens in solutions and gasses
• The higher the concentration gradient, the faster the diffusion rate
• Dissolved substances can move in and out of the cell membrane by diffusion
• The larger the surface area of the membrane, the faster the diffusion rate as more particles can pass through at once
• Temperature affects the speed of diffusion; warmer temperatures increase the kinetic energy of molecules so they diffuse faster
• The thinner the membrane is, the faster the diffusion rate as there are fewer barriers for particles to cross
• Diffusion is important because it allows cells to take up nutrients and oxygen needed for respiration
• Cells use diffusion to take in substances and to remove waste products