Diffusion

lmg719
Note by , created over 6 years ago

Biology (Cell and Simple Cell Transport) Note on Diffusion, created by lmg719 on 04/28/2013.

505
1
0
lmg719
Created by lmg719 over 6 years ago
Cell Transport
March April
Biology AQA 3.1.3 Cells
evie.daines
Biology AQA 3.2.5 Mitosis
evie.daines
GCSE Chemistry C4 (OCR)
Usman Rauf
Biology Unit 1a - GCSE - AQA
RosettaStoneDecoded
Cells and simple cell transport
lmg719
Biology AQA 3.1.3 Osmosis and Diffusion
evie.daines
GCSE Biology, Module B4
jessmitchell
GCSE AQA Biology 2 Cells & Diffusion
Lilac Potato
AQA Biology 11.1 replication of DNA
Charlotte Hewson

Page 1

Dissolved substances have to pass through the cell membrane to get into or out of a cell. Diffusion is one of the processes that allows this to happen.

      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.        

Location                                      Particles move                                         From                                               To

GutLungs

Digested food ProductsOxygen

Gut cavityAlveolar air space

Blood in capillary of villusBlood circulating around the lungs

Remember, particles continue to move from a high to a low concentration while there is a concentration gradient.

In the lungs, the blood will continue to take in oxygen from the alveolar air spaces provided the concentration of oxygen there is greater than in the blood. Oxygen diffuses across the alveolar walls into the blood, and the circulation takes the oxygen-rich blood away.

Diffusion

Examples of Diffusion

Diffusion in the Lungs