Diffusion

• DIFFUSION - Spreading out of particles from an area of high concentration to an area of lower concentration.
• DIFFUSION - happens in both solutions and gases, particles in these substances are free to move about randomly
• the simplest type of diffusion is when different gases diffuse through each other e.g. smell of perfume diffuses through the air
• The bigger the concentration gradient (difference in concentration) the faster the diffusion rate
• A higher temperature will also give a faster diffusion rate because the particles have more energy, so can move around faster
• CELL MEMBRANE - Only very small molecules can diffuse through cell membranes - like oxygen,glucose, amino acids and water. Big molecules like starch and proteins cant fit through the membrane