movement of particles in and out of cells

• diffusion is the movement of particles from an area of high concentration to an area of low concentration
• the greater the surface area the greater the rate of diffusion as there is more space for the particles to move through
• the bigger the concentration gradient the greater the rate of diffusion
• the larger the distance the slower the rate of diffusion, as the particles have to travel further
• the higher the temperature the faster the rate of diffusion as the particles are moving faster so they collide more often
• osmosis is the movement of water molecules from a region of high water potential to a region of low water potential across a partially permeable membrane
• a hypertonic solution is a solution with a lower water potential than the cell
• an isotonic solution is a solution with the same water potential as the cell
• a hypotonic solution is a solution with higher water potential than the cell
• active transport is the movement of molecules from a low concentration to a high concentration across a cell membrane against a concentration gradient
• active transport requires energy
• active transport requires carrier proteins