Membrane Structure

1. Cell membranes of unicellular organisms are ______so the organism can move.

2. What is meant by homeostasis?

3. Homeostasis is also called ______.

4. Give 7 functions of the plasma membrane.

a.

b.

c.

d.

e.

f.

g.

5. What is meant by the term selectively permeable?

6. Fluid inside the cell is called ______.

7. A ______bilayer makes up most of the cell membrane.

8. Are phospholipids heads polar or nonpolar?the tails?

9. How many fatty acid chains are in a phospholipid?

10. The ______describes the appearance of the cell membrane.

11. Why is the cell membrane said to act like a fluid?

12. What causes the mosaic pattern of the cell membrane when viewed from above?

13. The phospholipid ______of the cell membrane allows ______molecules to pass through easily, but ______do NOT.

14. Materials soluble in ______can pass easily through the cell membrane.

15. Because the cell membrane is ______, only ______molecules and larger ______molecules can move through easily.

16. List 3 substances that pass easily through the cell membrane.

17. ______, ______molecules larger than water, and large ______molecules do NOT move easily through the phospholipids of the cell membrane.

Types of Membrane Transport

18. Simple ______requires NO energy to move things across the cell membrane.

19. With simple diffusion, molecules move from an area of ______concentration to an area of ______concentration.

20.Why is diffusion considered a passive process?

21. With diffusion, molecules move by their own natural ______energy or energy of motion.

22. When solutes diffuse through a membrane, they move from ______to ______concentration.

23. ______is the diffusion of ______across a cell membrane.

24. If water potential is HIGH, solute concentration is ______.

25. If water potential is LOW, solute concentration is ______.

26. Water moves from ______water potential to ______water potential.

27. Water diffuses through the pores called ______of the cell membrane.

28. An isotonic solution has ______solute concentration with cell.

29. What is meant by NO NET movement?

30. Hypotonic solutions have ______solute concentration than a cell.

31. Hypertonic solutions have ______solute concentration than a cell.

32. Complete the following table:

Direction of Osmosis
Environmental Condition / Net Movement of water / What happens to cell
Hypotonic
Hypertonic
Isotonic

33. ______occurs whenever water moves into the cells causing them to swell and burst.

34. ______occurs whenever water moves out of a cell & the cell shrinks in size.

35. Explain what happens to a red blood cell placed in:

a. distilled water

b. a concentrated salt solution

36. Complete the following drawings.

37. Plants prefer ______environments, while animal cells do best in ______environments.

38. Passive transport does ______require additional energy & moves materials from ______to______concentration.

39. Give 2 examples of passive transport in cells.

40. ______diffusion is a type of ______transport because energy is NOT required.

41. Facilitated diffusion uses ______proteins to help move materials from ______to ______concentrations.

42. Name 2 materials that move into or out of cells by facilitated diffusion.

43. Name 2 types of transport proteins found in cell membranes.

44. Channel proteins have an opening or ______through which molecules can passively move by ______diffusion.

45. Do all carrier proteins extend across the cell membrane?

46. Explain how these carrier proteins move materials across the membrane.

47. Some carrier proteins can change ______to move materials across the cell membrane.

48. ______transport requires additional energy to move materials.

49. Active transport uses cellular energy known as ______.

50. Active transport moves materials AGAINST the concentration gradient or from ______to ______concentration.

51. The ______pump is an example of active transport.

52. The sodium-potassium pump moves ______sodium ions out for every ______potassium ions moved into the cell creating voltage across the cell called the ______potential.

53. Moving very large particles out of the cell is called ______.

54. In exocytosis, wastes are moved out of the cell in ______that fuse with the cell membrane.

55. ______involves moving large particles into the cell.

56. Taking in large liquid droplets is called ______or "cell drinking".

57. ______endocytosis involves protein ______recognizing hormones to help move them into the cell.

58. Give 2 examples of molecules that enter the cell this way.

67. "Cell eating" is known as ______.

68. White blood cells engulfing bacteria is an example of ______.

69. ______is the opposite of exocytosis.

70. Label the plasma membrane parts below with the following terms: protein, channel protein, carbohydrate chains, hydrophilic heads, hydrophobic tails, plasma membrane