1. Chapter 7.2 & 7.4 Cell Transport

2. Cell Membrane Review
Essential for homeostasis
Selectively permeable

3. Membrane Structure Flexible (fluid) due to cholesterol
Made up of many parts (mosaic)
Lipid bilayer

4. Phospholipid Main part of cell membrane Hydrophilic head
Hydrophobic tails (lipid)

5. Two layers of phospholipids

8. Membrane Proteins
Have specific functions:
Identify cell
Receive info
Transport materials

9. Membrane Proteins (cont.)
Stroke: blood clot blocks O2 flow to brain
Affects Ca pump
Excess Ca causes
cell death

10. Membrane Proteins (cont.)
Drugs & Brain:
Over stimulate receptors

11. An Animal Cell’s Environment
Water, oxygen & glucose enter the cell
Water, wastes & carbon dioxide exit the cell

12. Chapter 7.4 Types of Transport
Insane in the Membrane

13. Passive Transport
Movement of molecules across cell membrane without energy
Ex: Diffusion, Osmosis & Facilitated Diffusion

14. 1. Diffusion Movement of solute molecules
Higher to lower concentration
Solutes: oxygen, salt

16. Diffusion

17. What happens to the particles over time?
WHY???

18. Diffusion Animation

19. 2. Osmosis Movement of water (solvent) molecules
Higher to lower concentration
Solvents dissolve solutes

20. Osmosis
H2O

21. What happens to the water level?
WHY???

22. Osmosis Animation

23. Homeostasis Connection
Solute & solvent want to be in equal concentrations

24. Osmosis
Solvent
Solute

25. 3. Facilitated Diffusion
Diffusion using proteins in cell membrane
Used for molecules that are large (Ex. Glucose)

26. 3. Facilitated Diffusion (cont.)
Molecules with a specific shape can pass through

27. Applying Concepts: Day 1  2 Egg Shell Lab
Vinegar diffused into egg shell
Shell: Base
Vinegar: Acid & H2O

28. Applying Concepts: Day 2  3 Egg Shell Lab
Water left egg by osmosis
Egg white: 90% H2O
Corn syrup: 25% H2O

29. Applying Concepts: Day 3  4 Egg Shell Lab
Water entered egg by osmosis

30. Active Transport
Process that moves molecules from lower concentration to higher concentration
Helps store molecules
Requires energy

31. Sodium-Potassium Pump
Example of active transport
Helps nerves and muscles function properly

32. Endocytosis & Exocytosis
Used when things are too large to pass through the cell membrane by any other method

33. Endocytosis
Process where cells ingest fluids, large particles, macromolecules & other cells

34. Examples of Endocytosis
Amoeba: unicellular organisms feeds this way
White blood cells: use endocytosis to engulf & destroy bacteria & viruses

35. Endocytosis

36. Exocytosis Process where cells release substances
Organelles fuse with cell membrane & release contents