Diffusion Movement of molecules from areas of high concentration to areas of low concentration across a membrane Movement continues until equilibrium is reached! Then there is no more NET movement of molecules.
Diffusion occurs as molecules move down a concentration gradient. No energy is needed for this to happen. *The steeper the concentration gradient, the faster the movement of molecules.
Why is this so important? -All important nutrients enter the cell by diffusion. -All wastes exit the cell by diffusion. EXAMPLE Oxygen diffuses from lungs into blood arteries
How does this relate to cell size? CELL SIZE LAB Homework must be complete to perform the lab. You will receive a zero for the lab if homework is not complete. Homework: Prelab assignment: 1. read Lab 6 Design a Cell Introduction 2. complete pre-lab questions 3. design two cells