Words of Wisdom:

"why will some1 search the entire house for the remote but wont get up and change the channel?" - HongNhung


  • Date Submitted: 02/22/2012 02:05 PM
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15th of September
Investigating surface area and diffusion
  * To be able to describe the process of diffusion
  * Investigate and explain the effect of surface area on the rate of diffusion and relate this to gas exchange in cystic fibroses.
Diffusion: The movement of molecules in which the particles travel from an area of high concentration to low concentration so that there is a downward gradient in movement. No energy is requires.
This gas changes
Diffusion is the fastest when there is a large surface area, a steep concentration and thin surfaces.
Cube cm | Surface area cm2 (length x height of all surfaces and add) | Volume cm3 (length x height x depth) | Surface area to volume ratio (divide surface area by volume) | Distance from the edge of the cube that has changed colour after 5 minutes |
0.5 | 0.5 x 0.5 x 6 = 1.5 | 0.5 x 0.5 x 0.5 = -0.125 | 1.5/0.125 = 12 | 2mm |
1.0 | 1.0 x 1.0 x 6 = 6 | 1.0 x 1.0 x 1.0 = 1 | 6/1 = 6 | 2mm |
2.0 | 2.0 x 2.0 x 6 =24 | 2.0 x 2.0 x 2.0 = 8 | 24/8 = 3 | 2mm |
3.0 3.0
Activity 2.3:
Gas exchange surfaces
Learning objective:
  * To be able to describe features of gas exchange surface areas
  * Explain how the mammalian lung is adopted for rapid gas exchange
  * Relate to the structures in the lung and their function
Proper name for the windpipe = trachea
Gas exchange is an exchange in oxygen and carbon dioxide in which the oxygen comes into the blood and the carbon dioxide leaves the blood.
Goblet cells produce mucus.
  1) Both the trachea and the branches have the cartilage but the bronchioles did not, that’s how I could tell them apart.

  3) The function of mucus is that so the bacteria can attach to it with its hair like structure. The mucus is moved to the back of the throat which is then destroyed in the stomach acid when swallowed
  4) Tracheas and branches havce cartilages to keep the airways open
  5) Artery walls are thicker due to muscle due to the high...


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