Exchange of materials

HideShow resource information
  • Created by: Maceyf
  • Created on: 08-04-17 21:12

osmosis

1.1 osmosis

  • osmosis is the diffusion of water
  • water diffuses from a dilute solution through a partally permeable membrane
  • water movies into or out of cells by osmosis through the cell membrane

osmosis refers to the movement of water molecules only

1.2 active transport

  • active transport allows cells to take in substances against a concertration gradient.
  • active transport uses energy from respiration
  • ions, from dilute solution and other substance such as sugur can be absorbed by active transport.
1 of 5

sports drink

1.3 the sports drink dilemma

they contan;

  • water to replace that lost when sweating
  • sugar used to replace what needed for creating energy
  • mineral ions for those lost in sweating

water just as effective for normal levels of exersie.

1.4 EXCHANGING MATERIALS- LUNGS

organisms have exchange surfaces (efficient exchange surfaces) : large surface area, thin walls, short diffusion path, efficent transport.

the lungs are adapted to be efficent exchange surface area.; alveoil highly adapeted for this. (thin walls, large surface area, good blood supple)

2 of 5

ventilation

1.5 VENTILATING THE LUNGS

ventilation happens due to changes of pressurre.

-

-

-

-

1.6 ARTIFICAL BREATHING AIDS

  • RESONS FOR THEM; alveoil damged, tubes narrowed, paralysed.
  • IRON LUNG in cyclinderair dran in and out to ceat pressure in vacum. (NEGTIVE PRESURE)
  • POSITIVE PRESSURE; bags of air likind to mask force air down trachea.
3 of 5

gut,plants

1.7 EXCHANGE IN GUT

  • villi lines the suface of the small intestine and are a very efficient exchange surface.
  • there job is to absorb soluble products of digestion by diffusion or active transprt.

they have: large surface are, thin walls, good blood supply.

1.8 EXCHANGE IN PLANTS

  • the stommata in plant leaves allow carbon dioxide to diffuse the leaf from the atmosphere
  • leaves are flat and thin with internal air spaces to increase the surface area for diffusion of gases
  • root hair cells incrase the surface area of the roots.

if the stomata loses to much water they can wilt

4 of 5

transpiration

1.9 TRANSPIRATION

  • water is lost from leaves by evaporation
  • the water vapour escapes the leaf through the stomata when they open to allow carbon dioxide to enter the leaf
  • wilting can protect the leaf from excessive water loss.
5 of 5

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Exchange of materials resources »