The net movement of molecules from an area of high concentration to an area of low concentration down a concentration gradient
What molecules enter and leave cells via simple diffusion through the cell membrane?
Small molecules e.g. oxygen, water, glucose, amino acids
What factors affect the rate of diffusion? (3)
Temperature
Concentration gradient
SA of cell membrane
Define osmosis.
The net movement of water molecules from an area of high water concentration to an area of low water concentration through a partially permeable membrane
What is active transport?
The movement of molecules across a cell membrane from an area of low concentration to an area of high concentration, against the concentrationgradient, using energy.
How is a percentage change in mass calculated?
percentage change = (change in mass/ initial mass) x 100