Year 1 Lesson 2: Travelling in and out of a cell - Osmosis - Diffusion

Osmosis supposes his toeses are roses.

Osmosis:-The description of osmosis is ' The movement of water across partially permeable cell membrane from a region of high water molecule concentration to a region of low water molecule concentration.

Things that need to get into a cell (travel via blood vessels):
Nutrients; minerals and vitamins, glucose, amino acids, lipids-fatty acids and glycerol, oxygen.

Things that need t oget out of a cell (via the veins):
C02, Urea

An animal cell is fully permeable to water. Don't get your cells wet, its bad for them, they explode.

Diffusion:- The movement of particles down a concentration gradient from high to low. Diffusion can be assisted by:

1.Increasing blood supply
2.Increasing surface area
3.Increasing concentration gradient
3 Increasing heat (not in biological systems though)

*Lungs have a very high surface area
Root cells and leaves have a very high surface area. Both are specialised.

I carried out two tests to demonstrate osmosis and diffusion. I will draw diagrams for them, but not today. They were very fun, one involved amonia, a boiling tube and litmus paper. The other one involved Visking tube (henceforth known as Viking tube), Starch, Glucose and Iodine.

Plant cells have cell WALLS this acts as a sort of armour. This means that the walls will prevent water freely passing into it and damaging it.