“White board challenge” Diffusion Gr C: Explain what diffusion is using particle mode. Gr B: Link diffusion to molecular movement in and out of a cell. Gr A: Evaluate factors affecting rate of diffusion. Key Words Diffusion Concentration Particle Cell surface membrane Starter “White board challenge” Starter and introduction of LO’s Recap particle theory Breakdown key words Experiment AFL activity Illustrate the particles in a solid, liquid and gas.

Particles theory All matter is made up of tiny particles called atoms. There are a range of different types of atom. E.g. oxygen, carbon, gold, silver, nitrogen, lithium, sodium, Atoms can form themselves into a range of different states. (Solid, liquids, gases) Each state of matter is independent and they all have different properties.

Diffusion Key Word Alert Diffusion occurs when particles spread. They move from a region where they are in high concentration to a region where they are in low concentration. Diffusion happens when the particles are free to move. This is true in gases and for particles dissolved in solutions.

Which of these are example of diffusion? Diffusion Examples Activity Which of these are example of diffusion? Diffuse or not? A spray of perfume in an open room. Food dye squirted into water. Salt water mixed with water A solid cube of gold mixed with water. A block of carbon in an open room. Key notes Diffusion only occurs with gases, liquids and solutions. Diffusion occurs as a result of the random movement of particles. Diffusion continues until an equilibrium is achieved. The random movement of particles is due to their kinetic energy

“White board challenge” Diffusion Gr C: Explain what diffusion is using particle mode. Gr B: Link diffusion to molecular movement in and out of a cell. Gr A: Evaluate factors affecting rate of diffusion. Key Words Diffusion Concentration Particle Cell surface membrane Starter “White board challenge” Starter and introduction of LO’s Recap particle theory Breakdown key words Experiment AFL activity Illustrate the particles in a solid, liquid and gas.

Semi permeable membrane Key Word Alert Semi permeable membrane A semi permeable membrane (or partially permeable membrane). Is a membrane which only allows certain particle to pass through it. If the particles are to large or have an electrical charge they are unable to pass through the membrane. Key Protein Glucose Water Semi- permeable membrane

Diffusion in living organisms

“White board challenge” Diffusion Gr C: Explain what diffusion is using particle mode. Gr B: Link diffusion to molecular movement in and out of a cell. Gr A: Evaluate factors affecting rate of diffusion. Key Words Diffusion Concentration Particle Cell surface membrane Starter “White board challenge” Starter and introduction of LO’s Recap particle theory Breakdown key words Experiment AFL activity Illustrate the particles in a solid, liquid and gas.

Variables affecting rate diffusion Having a larger surface area means that more particles can pass through the barrier or membrane at once. Small barriers only allow a small amount rate of diffusion By maintains a concentration gradient diffusion can continue to occur as particles spread through the membrane/barrier. Diffusion distance Temperature Variables affecting rate diffusion Diffusion surface area Maintaining Concentration gradient When additional heat is added to a solution the particles gain kinetic energy, causing them to move round much faster. This increases the collision rate between each other and makes them spread much faster. If molecules have to pass through a large barrier it is much more difficult for them. That’s why it is important for the barrier/membrane to be as thin as possible.

“White board challenge” Diffusion Gr C: Explain what diffusion is using particle mode. Gr B: Link diffusion to molecular movement in and out of a cell. Gr A: Evaluate factors affecting rate of diffusion. Key Words Diffusion Concentration Particle Cell surface membrane Starter “White board challenge” Starter and introduction of LO’s Recap particle theory Breakdown key words Experiment AFL activity Illustrate the particles in a solid, liquid and gas.