Your SlideShare is downloading. ×
Powerpoint cell membrane transport   copy
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Powerpoint cell membrane transport copy

8,529

Published on

Published in: Technology, Education
2 Comments
3 Likes
Statistics
Notes
No Downloads
Views
Total Views
8,529
On Slideshare
0
From Embeds
0
Number of Embeds
5
Actions
Shares
0
Downloads
290
Comments
2
Likes
3
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Transport through cell membranes Biology, Cell membranes and Transport 1
  • 2. Transport through cell membranes The phospholipid bilayer is a good barrier around cells, especially to water soluble molecules. However, for the cell to survive some materials need to be able to enter and leave the cell. Mechanisms:4. DIFFUSION6. OSMOSIS8. ACTIVE TRANSPORT Biology, Cell membranes and Transport 2
  • 3. DEFINITIONS DIFFUSION: the net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement. OSMOSIS: the diffusion of water molecules from a region of their higher concentration (dilute solution) to a region of their lower concentration (concentrated solution), through a partially permeable membrane. ACTIVE TRANSPORT: the movement of ions in or out of a cell through the cell membrane, from a region of their lower concentration to a region of their higher concentration against a concentration gradient, using energy released during respiration. Biology, Cell membranes and Transport 3
  • 4. Diffusion of liquids Biology, Cell membranes and Transport 4
  • 5. •Diffusion is the net movement of molecules (orions) from a region of their high concentration toa region of their lower concentration.The molecules move down a concentration gradient.Molecules have kinetic energy, which makes themmove about randomly.As a result of diffusion molecules reach anequilibrium where they are evenly spread out.This is when there is no net movement of moleculesfrom either side. AS Biology, Cell membranes and Transport 5
  • 6. DIFFUSIONDiffusion is a PASSIVE process which means no energy is usedto make the molecules move, they have a natural kinetic energy. AS Biology, Cell membranes and Transport 6
  • 7. Diffusion of Bromine Biology, Cell membranes and Transport 7
  • 8. Diffusion of Bromine Biology, Cell membranes and Transport 8
  • 9. Diffusion through a membrane Cell membrane Inside cell Outside cell Biology, Cell membranes and Transport 9
  • 10. Diffusion through a membrane Cell membrane diffusion Inside cell Outside cell Biology, Cell membranes and Transport 10
  • 11. Diffusion through a membrane Cell membrane Inside cell Outside cell EQUILIBRIUM Biology, Cell membranes and Transport 11
  • 12. AS Biology, Cell membranes and Transport 12
  • 13. AS Biology, Cell membranes and Transport 13
  • 14. What determines the rate of diffusion? There 4 factors: The steepness of the concentration gradient. The bigger the difference between the two sides of the membrane the quicker the rate of diffusion. Temperature. Higher temperatures give molecules or ions more kinetic energy. Molecules move around faster, so diffusion is faster. The surface area. The greater the surface area the faster the diffusion can take place. This is because the more molecules or ions can cross the membrane at any moment. The type of molecule or ion diffusing. Large molecules need more energy to get them to move so they tend to diffuse more slowly. Non-polar molecules diffuse more easily than polar molecules because they are soluble in the AS Biology, Cell membranes and non polar phospholipid tails. Transport 14
  • 15. Molecules that diffuse through cell membranes Oxygen – Non-polar so diffuses very quickly. Carbon dioxide – Polar but very small so diffuses quickly. Water – Polar but also very small so diffuses quickly. Biology, Cell membranes and Transport 15
  • 16. Osmosis‘The diffusion of water from an area of high concentration of water molecules (high water potential) to an area of low concentration of water (low water potential) across a partially permeable membrane.’ Biology, Cell membranes and Transport 16
  • 17. Osmosis CONCENTRATED SOLUTION DILUTE SOLUTION Cell membrane partiallySugar molecule permeable. VERY Low conc. of water molecules. Low water potential.VERY High conc. Outside cell Inside cellof watermolecules. Highwater potential. Biology, Cell membranes and Transport 17
  • 18. Osmosis Cell membrane partially permeable. Low conc. of water molecules. Low water OSMOSIS potential.High conc. of Inside cell Outside cellwater molecules.High waterpotential. Biology, Cell membranes and Transport 18
  • 19. Osmosis Cell membrane partially permeable. OSMOSIS Inside cell Outside cellEQUILIBRIUM. Equal water concentration on each side.Equal water potential has been reached. There is no net AS Biology, Cell membranes andmovement of water Transport 19
  • 20. AS Biology, Cell membranes and Transport 20
  • 21. AS Biology, Cell membranes and Transport 21
  • 22. OSMOSIS IN ANIMAL CELLS Red blood cells Biology, Cell membranes and Transport 22
  • 23. OSMOSIS: Slides of red blood cells Biology, Cell membranes and Transport 23
  • 24. OSMOSIS IN PLANT CELLS AS Biology, Cell membranes and Transport 24
  • 25. ACTIVE TRANSPORT AS Biology, Cell membranes and Transport 25
  • 26. Biology, Cell membranes and Transport 26
  • 27. Biology, Cell membranes and Transport 27
  • 28. ACTIVE TRANSPORT: Carrier + energy Biology, Cell membranes and Transport 28
  • 29. Comparison table Biology, Cell membranes and Transport 29
  • 30. Endocytosis is the case when a molecule causes the cell membrane to bulge inward, forming a vesicle. Phagocytosis is the type of endocytosis where an entire cell is engulfed. Pinocytosis is when theexternal fluid is engulfed. Receptor-mediated endocytosis occurs whenthe material to be transported binds to certain specific molecules in the membrane. Examples include the transport of insulin and cholesterol into animal cells. AS Biology, Cell membranes and Transport 30
  • 31. Cell Membrane - Function - Endocytosis The cell membrane can also engulf structures that are much too large to fit through thepores in the membrane proteins this process is known as endocytosis. In this process themembrane itself wraps around the particle and pinches off a vesicle inside the cell. In this animation an ameba engulfs a food particle. AS Biology, Cell membranes and Transport 31
  • 32. ExocytosisThe opposite of endocytosis is exocytosis. Large molecules that are manufactured in the cell are released through the cell membrane. Biology, Cell membranes and Transport 32
  • 33. AS Biology, Cell membranes and Transport 33
  • 34. Vesicle-mediated transport Vesicles and vacuoles that fuse with the cell membrane may beutilized to release or transport chemicals out of the cell or to allow them to enter a cell. Exocytosis is the term applied when transport is out of the cell. AS Biology, Cell membranes and Transport 34

×