1. Cell Membrane Transport

2. Cell membrane transport There are 2 types of cell membrane transport: Passive Transport Substance move from High concentration to low concentration -no energy required Active Transport Substance move from low concentration to high concentration -energy (ATP) required

3. Another perspective on passive and active transport

4. Passive Transport Diffusion The movement of particles from areas of high concentration to low concentration

5. Diffusion Factors that influence the rate of diffusion Temperature Pressure Electrical currents Molecular size

6. Equilibrium the concentrations of particles are the same on both sides of the membrane

7. Facilitated Diffusion Particles flow from high concentration to low concentration but this time they need the help of proteins to get through the cell membrane.

8. Facilitated diffusion

9. Osmosis The diffusion of water across a selectively permeable membrane Important in maintaining cell homeostasis Water flows to side of membrane where the water concentration is lower until equilibrium is reached

10. Osmosis Osmosis is controlled by the amount of solutes on either side of a membrane

11. Osmosis – Types of Solutions When dealing with osmosis, water can either move into the cell or out of it. The solute cannot move to equal out the concentration of solutions, so the water has to. We describe the solutions that cells are in as either hypotonic, isotonic, or hypertonic.

12. Isotonic Solution Isotonic solution – Concentration of solute is the same in the cell and the area around the cell. Water moves in and out at equal rates.

13. Isotonic solution

14. Hypotonic Solution Hypotonic Solution – Concentration of solute is lower in the solution than in the cell. Net movement of water INTO the cell.

15. Hypotonic solutions Since water moves into the cell the cell, animal cells can explode Cytolysis

16. Plant and animal cells in a hypotonic solution Turgor Pressure – central vacuole is full; pressure against the cell wall

17. Hypertonic Solution Hypertonic solution – concentration of solute is higher in the solution than in the cell. Net movement of water OUT of the cell.

18. Hypertonic solutions Since water moves out of the cell the cell will shrink

19. Plant and animals cells in a Hypertonic Solution Plasmolysis: shrinking of cytoplasm due to osmosis

20. Active Transport Molecules move from low concentration to high concentration Requires energy….why?

21. Active Transport Molecular Transport Protein Pumps Small molecules and ions carried across the cell membrane by proteins in the membrane that act like pumps (low  high) Bulk Transport Endocytosis – in! Exocytosis – out!

22. Sodium Potassium Pump

23. Other membrane transport activities that require energy Endocytosis Engulfing of large particles or liquids from outside the cell

24. 2 types of Endocytosis Phagocytosis Engulfing of large particles from outside the cell Pinocytosis Engulfing of liquids from outside the cell

25. Other membrane transport activities that require energy Exocytosis Release of large particles or liquids from inside the cell Inside the cell Outside the cell

27. Which of the following allows cells to recognize each other as self or foreign? 1. Channel Proteins 2. Cholesterol 3. Phospholipids 4. Glycoproteins 10

28. The inside of the cell membrane consists of 1. Phosphate heads 2. Fatty acid tails 3. Extracellular Matrix 4. Carbohydrate chains 10

29. Which of the following components of the cell membrane affects the fluidity of the cell membrane? 1. Glycoproteins 2. Glycolipids 3. Cholesterol 4. Extracellular matrix 10

30. Which type of protein is responsible for receiving messages from hormones? 1. Channel protein 2. Carrier protein 3. Cell Recognition Protein 4. Receptor Protein 10

31. The movement of particles from high concentration to low concentration is called 1. Osmosis 2. Diffusion 3. Endocytosis 4. Exocytosis 10

32. The diffusion of water is called 1. Active transport 2. Endocytosis 3. Exocytosis 4. Osmosis 10

33. The movement of particles across a membrane that requires energy (ATP) is called 1. Passive transport 2. Active transport 3. Aquaporins 4. Semi-permeable 10

34. This diagram is an example of what membrane transport? 1. Diffusion 2. Facilitated diffusion 3. Endocytosis 4. Exocytosis 10

35. This diagram is an example of what membrane transport? 1. Diffusion 2. Facilitated diffusion 3. Endocytosis 4. Exocytosis 10