Ch. 5 Review

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’s the difference between the two?

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? • In • 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