Diffusion and Osmosis Why is diffusion and Osmosis

Diffusion and Osmosis

Why is diffusion and Osmosis important? • Quick review: – What do all of our cells need? • • Oxygen Water Nutrients Get rid of CO 2 – What is a selectively permeable membrane? • Membrane which allows certain materials to pass through while stopping other materials

Diffusion • Movement of a substance from a high concentration to a lower concentration – This occurs until the substance has reached equilibrium (balanced) Diffusion

Diffusion (cont) • Each and every one of our cells need to take in and release a lot of different material. • This happens through diffusion. – High amount of O 2 outside of cell – Low amount of O 2 inside the cell • O 2 moves across selectively permeable membrane

Diffusion in your lungs

Osmosis • This is a type of diffusion. • The only difference is: – Osmosis is ONLY the movement of WATER across a selectively permeable membrane. • Usually water isn’t pure. It’s not 100% water molecules (H 20). – It usually contains other contaminants like metals, flouride, iron, bacteria, salt, etc…

Osmosis (cont) • Distilled water is purified water without salts and impurities. – Cannot find it in nature. – Should not drink distilled water. Why? – If you’re drinking pure 100% water, your cells will take in water due to osmosis, and rupture. It’s possible you will have blood in your urine. 100% pure water 70% water (cell)

Effect of osmosis on RBC’s

Effect of Temperature on diffusion • Colder temperatures decrease diffusion – Molecules are moving slower • Warmer temperatures increase diffusion – Molecules are moving faster • Moral of the story: – If you’re going to fart, fart in a cold room rather than a hot room. – The smell won’t diffuse as fast and stink up the room.

Osmosis and Diffusion