1. Ch. 5 Review
5.1 Passive Transport

2. Differentiate the terms solute and solvent.
Solute = substance being dissolved
Solvent = substance doing the dissolving

3. What is the solvent inside and outside of the cell?
Water

4. What are the four components of the cell membrane?
Phospholipids
Carbs
Proteins – both integral and peripheral
Steroids (cholesterol)

5. What does selectively permeable or semi-permeable mean?
Only certain things can pass through

6. What are the two main types of transport
What are the two main types of transport? What’s the difference between the two?
Passive transport
Active transport
No ATP needed
Movement of particles from high to low concentration
ATP needed
Movement of particles from low to high concentration

7. List the four types of passive transport.
Simple diffusion
Osmosis
Facilitated diffusion
Diffusion through ion channels

8. Define diffusion. Why does it occur?
Movement of particles from high conc. to low
Occurs naturally due to kinetic energy of particles

9. Give an example of diffusion.
Food coloring in water
Perfume/cologne
Loss of helium from a balloon
Smoke
Oxygen, carbon dioxide, and other small nonpolar molecules across the cell membrane

10. What is equilibrium?
Particles are spread evenly throughout a space

11. Do the particles stop moving in equilibrium?
No!
Why not?
They have kinetic energy!

12. What is osmosis?
Movement of water from high to low conc. through a membrane

13. Define hypertonic, hypotonic, and isotonic.
Hypertonic = high solute
Hypotonic = low solute
Isotonic = same solute

14. In which of those solutions are the particles in equilibrium?
Isotonic

15. Which way does water flow when cells are in a hypotonic solution?
What happens to animal cells?
Cytolysis
What happens to plant cells?
Turgor pressure

16. What is cytolysis? Cell bursting
Why don’t plant cells experience cytolysis?
They have cell walls

17. What is turgor pressure?
Pressure of membrane pushing against the cell wall

18. Which way does water flow when cells are in a hypertonic solution?
Out
What happens to animal cells?
Crenation
What happens to plant cells?
Plasmolysis

19. What is crenation?
Cell shrinking/shriveling

20. What is plamolysis?
Cell membrane pulls away from cell wall

21. If you are stranded at sea, why shouldn’t you drink the ocean water?
It’s too salty! You would be putting your cells in a hypertonic environment which would cause them to lose water!!

22. What is facilitated diffusion?
Assisted diffusion
Movement of particles from high conc. to low through a transport protein called a carrier protein

23. Do carrier proteins transport lots of different types of molecules or one type of molecule?
One type… they are specific!

24. List the steps of facilitated diffusion.
Carrier protein binds to molecule
Carrier protein changes shape
Molecule moves through
Molecule released on other side; carrier protein returns to original shape and is reusable

25. What types of molecules move by facilitated diffusion?
Glucose
Small polar molecules

26. What is diffusion through ion channels?
Movement of ions from high conc. to low through carrier proteins called ion channels or channel proteins
Ion channels are also specific – they only move one type of ion

27. What is the everyday word for an ion?
electrolyte

28. Why can’t ions move through the cell membrane on their own?
They are charged – repelled by nonpolar interior of cell membrane

29. Some ion channels open and close. What are they called?
Gated channels

30. What controls the opening/closing of gated ion channels?
Cell membrane stretching
Electrical signals
Chemical signals

31. What are some common ions?
sodium (Na+)
potassium (K+)
calcium (Ca2+)
magnesium (Mg+)
chlorine (Cl-)
phosphate (PO4-)
bicarbonate (HCO3-)

32. Why are ions important? Heartbeat and nerve function Fluid balance
Oxygen delivery
Acid-base balance

33. 5.2 Active transport

34. What’s the difference between active and passive transport?
Active transport moves substances against the gradient
Active transport requires ATP!!

35. List the types of active transport
Protein pumps
Endocytosis
Exocytosis

36. What is a protein pump?
Transport protein that moves molecules from low to high conc. ; requires energy

37. What are the basic steps of how protein pumps work?
Protein binds to molecule
Protein changes shape; this requires ATP!
Molecule moves through protein and is released on the opposite side
Protein returns to original shape and is reusable

38. Give an example of a protein pump.
Sodium-potassium pump

39. Cells must maintain higher sodium _______ and higher potassium _________ the cell.
Outside
Inside

40. Sodium and potassium always move in a ________ ratio.
3:2

41. Describe how the sodium-potassium pump works.
3 sodiums bind to the pump on the inside of the cell
Protein splits a phosphate from ATP and releases energy; the free phosphate binds to the pump causing it to change shape
3 sodiums move out
2 potassiums bind to pump on outside of cell
Phosphate is released from pump causing it to change shape
Potassiums move in
Protein returns to original shape and is reusable

42. Define endocytosis.
Talking bulky materials into a cell

43. What are the two types of endocytosis?
Pinocytosis
Phagocytosis
What’s the difference between the two?
Pinocytosis – fluids, cell “drinking”
Phagocytosis – solids, cell “eating”

44. How does endocytosis work?
Cell membrane folds inward around material to be ingested
Membrane pinches off inside of cell forming a vesicle
Vesicle fuses with a lysosome to digest materials

45. Define exocytosis.
Forcing material out of the cell in bulk

46. How does it work?
Vesicle containing material fuses with the cell membrane releasing contents outside

47. The cell membrane changes shape… this requires ___________.
Energy

48. Give three examples of materials released from a cell by exocytosis.
Hormones
Proteins
Wastes