1. maintaining homeostasis
Cell Transport
maintaining homeostasis
Chapter 5
Miss Colabelli

2. Passive Transport Does NOT require any ATP or energy
Happens automatically
Channels may be used in cell membrane

3. Passive Transport
This type of transport moves from an area of high concentration to low concentration

4. Passive Transport Three types of passive transport Simple diffusion
Osmosis
Facilitated Diffusion
These processes DO NOT REQUIRE ENERGY

5. Diffusion Type of passive transport
When molecules move from an area of higher concentration to an area of lower concentration until equilibrium is met

6. What affects the rate of diffusion?
Concentration of the solution
Temperature of the solution
Pressure also speeds up particle motion

7. Concentration The amount of dissolved solute in a solution
Molecules will move to an area less concentrated
Molecules diffuse through the cell membrane of cells

8. Concentration gradient
The difference in concentration in a solution between a cell and its surroundings

9. Concentration Gradient
No gradient - even distribution
Concentration to the right
Concentration Gradient

10. Increase Rate of Diffusion
Temperature
Molecules move faster in higher temperatures
Pressure
Increasing pressure also increases rate of diffusion

11. Equilibrium
This occurs when there is no longer a concentration gradient
Molecules are evenly dispersed but still continue to move randomly

12. Cell Membrane Movement through membrane
Cell membrane is surrounded by water
Phospholipid bilayer

13. Cell Membrane Forms by itself in water Proteins imbedded Markers
Receptors
Channels

14. Diffusion in cells
Small molecules diffuse in and out of the cell to reach equilibrium on both side of the membrane

15. Osmosis Diffusion of water across a biological membrane
From an area of high concentration to low concentration of WATER
Comparing concentrations

16. Osmosis in Cells Cells are surrounded and filled with water
Water can move freely through the membrane

17. Direction of Osmosis

18. Hypertonic Outside cell is more concentrated than the cell ex:
The solution with 20% salt is hypertonic compared to the 10% salt solution
10% salt solution inside the cell
20% salt solution outside the cell

19. Hypotonic Outside the cell is less concentrated than cell ex:
The solution with 10% salt is hypotonic compared to the 20% salt solution
10% salt solution outside the cell
20% salt solution inside the cell

20. Isotonic Equal concentrations ex: Equilibrium is reached
10% salt solution outside the cell
10% salt solution inside the cell

21. Osmotic Pressure Net movement of water into cells
Determined by solute concentration

22. Osmosis - hypertonic Higher solute concentration in solution
Ex: a cell in salt water
When molecules are too large to fit through cell membrane or protein channels
Water will diffuse OUT of the cell to reach equilibrium
Cell shrinks

23. Osmosis - hypotonic Lower solute concentration in solution
Ex: a cell in pure water
If molecules are too large to fit through cell membrane or protein channels
Water will diffuse INTO the cell to reach equilibrium
Cell swells - may burst!

24. Osmosis - Isotonic Equal concentration in solution
If molecules are too large to fit through cell membrane or protein channels
Water will diffuse IN AND OUT of the cell to maintain equilibrium

25. Osmosis in Plant Cells Turgor Pressure
Pressure on the walls of the plant cells due to vacuole filling
Increase in turgor pressure is due to an increase of water to cell
Plasmolysis
When a cell shrinks due to lack of water

26. Red Onion Cells - Isotonic

27. Red Onion Cells - Hypertonic

28. Red Onion Cells - Hypotonic

29. Facilitated Diffusion
When the cell membrane has protein channels (carrier proteins) where materials are transported in or out of cell
NO energy needed for this process

30. Active Transport Against concentration gradient
From an area of low concentration to an area of high concentration
Requires cell energy (ATP) because you’re going AGAINST concentration gradient

31. 3 types of active transport
Three types of active transport
Active transport
Endocytosis
Exocytosis
These processes REQUIRE ENERGY

32. Active Transport Protein channels embedded in cell membrane
Gated channels
Need energy to open
Protein changes shape when energy is used

33. Sodium/Potassium Pump
Step 1: 3 sodium ions bind to carrier protein
Step 2: ATP binds to carrier protein and changes shape allowing Na+ to move out of the cell
Step 3: 2 potassium ions move into carrier protein
Step 4: ATP binds to carrier protein and changes shape allowing K+ to move into the cell
P in the cup – potassium in the cell

34. Sodium/Potassium Pump

35. Sodium Potassium Pump

36. Movement in Vesicles Endocytosis - INTO the cell
Cell membrane is used to create a vesicle around particles
Phagocytosis
Particle ingestion
Pinocytosis
Liquid ingestion

37. Movement in Vesicles Exocytosis - OUT of the cell
Vesicles created in the cell fuse with cell membrane and release particles/liquids
Known as bulk transport