Cellular Transport

1. Cellular Transport

2. What about Cellular Transport? • Nutrients and wastes move into and out of the cell – this is called cellular transport • Nutrients are needed at different amounts and move in and out of the cell to maintain homeostasis

3. What is needed in mammalian cells?

4. What’s needed for E.coli (a type of bacteria)

5. Why such a huge difference? • Because mammals have several different cells that perform different tasks and would require different nutrients to perform those tasks

6. Cellular Transport in other organisms

7. Osmosis in an Elodea Leaf • Background information • Elodea is a common freshwater plant that is frequently used to decorate aquariums. • The leaves of Elodea are only two cells thick and are ideal for the microscopic study of the effects of osmotic solutions.

8. Osmosis in an Elodea Leaf • Freshwater is hypotonic to Elodea and maintains normal turgor (osmotic) pressure in the plant.  • A hypotonic solution is a solution that contains less (hypo) solutes than the cytoplasm of the cell. • Thus, a hypotonic solution has more water than the celland water has a tendency to move (diffuse) into the cell.

9. Background information • In plants this inward "pressure" produces rigidity of the cell as the plasma membranes are pushed against the cell walls.

10. Osmosis in an Elodea Leaf • Plant cells do not rupture because the cell walls resist the outward expansion of the plasma membrane.

11. Elodea in hypotonic solution

12. What happens to Elodea in hypertonic solution? Water leaves the cell

13. Osmosis in single-celled organisms

14. Osmosis in Paramecium Background information Paramecium is a freshwater protozoa (single-cell eukaryotes) and may be obtained by culture (purchased or maintained in the laboratory) or in the field by sampling scum of stagnant water.

15. Osmosis in Paramecium • Freshwater is hypotonic to Paramecium, and results in the osmotic movement of water into the cell. • Specialized organelles called contractile vacuoles function in the homeostatic maintenance of normal turgor pressure

16. Paramecium

17. Osmosis in human blood cells

18. What happens in a red blood cell in an Isotonic solution? Red blood cells Plant cell

19. What happens in a red blood cell in a Hypotonic solution? Because there is only a cell membrane the blood cell could burst Red blood cells Plant cell

20. What happens in a red blood cell in a Hypertonic solution? Red blood cells Plant cell

21. Types of Diffusion

22. Facilitated Diffusion a form of Passive Diffusion • Movement of molecules such as glucose through the cell membrane through channel proteins • Does not require the input of energy

23. When transport goes against the grain

24. Active Transport • Movement of material from low concentration to high concentration or against the concentration gradient • Requires energy

25. Movement of nutrients and waste in unicellular organisms

26. Endocytosis Phagocytosis • The process of moving large particles • into the cell by endocytosis • A type of active transport that moves large amounts of material into the cell • Endo= into Cyto= cell

27. Exocytosis • The removal of large amounts of materials out of the cell • Exo= out of Cyto= cell