NSB 121 – GENERAL BIOLOGY I
1.
2.
3.
4.
5.
6.
CHAPTER 05 – STUDY GUIDE
What are cellular membranes composed of? Why are they called a fluid mosaic?
What is the function of cholesterol in animal cell membranes?
How do the fatty acid tails of phospholipids prevent them from packing tightly together?
What are the six different types of functions that proteins can perform in a plasma membrane?
What is a selectively permeable membrane?
Why is it believed that phospholipids were the key ingredient that allowed the first cellular membranes
to form?
7. What is diffusion?
8. Why is diffusion across a membrane called passive transport?
9. Using diagrams, describe the diffusion process through a permeable membrane.
10. What is osmosis?
11. Indicate the direction of net water movement between two solutions – a 0.5% sucrose solution and a 2%
sucrose solution – separated by a membrane not permeable to sucrose.
12. What is tonicity?
13. How is an animal cell affected when placed into an isotonic solution? A hypotonic solution? A hypertonic
solution?
14. How is a plant cell affected when placed into an isotonic solution? A hypotonic solution? A hypertonic
solution?
15. What is osmoregulation?
16. What is plasmolysis? In what type of cell can this process occur? Why?
17. What is facilitated diffusion?
18. How do transport proteins contribute to a membrane’s selective permeability?
19. How are molecules transported across the cellular membrane in facilitated diffusion?
20. Can water easily diffuse across the cellular membrane? Why?
21. What are aquaporins?
22. What is active transport?
23. Describe the active transport of one solute across a cellular membrane. How does this change if two
molecules are involved?
24. Cells actively transport Ca2+ out of the cell. Is calcium more concentrated inside or outside of the cell?
Explain.
25. Name and briefly describe the two mechanisms used by the cell to move large molecules across
membranes.
26. Name and briefly describe the three types of endocytosis.
27. As a cell grows, its plasma membrane expands. Does this involve endocytosis or exocytosis? Explain.
28. What does the cell use chemical reactions for?
29. Define energy.
30. Name and briefly describe the two different kinds of energy.
31. Define thermodynamics.
32. Enunciate the two laws of thermodynamics.
33. How does the second law of thermodynamics explain the diffusion of a solute across a membrane?
34. What is entropy?
35. How does the energy efficiency of a cell compare to that of a car?
36. Define heat.
37. Define chemical energy.
38. What are the two forms of chemical reactions?
39. Describe what happens in an exergonic reaction. Give an example of an exergonic reaction.
40. Describe what happens in an endergonic reaction. Give an example of an endergonic reaction.
41. Define metabolism.
42. What is a metabolic pathway?
43. How does energy coupling take place in the cell?
44. What does ATP stand for? What is its function? How is it composed?
45. What happens during the phosphorylation process?
46. What are the three different types of cellular work? What molecule drives all three of them?
47. Explain how ATP transfers energy from exergonic to endergonic processes in the cell.
48. Define activation energy (EA)
49. What are enzymes and how do they participate in biochemical reactions?
50. What is an enzymatic substrate?
51. What is the active site of an enzyme?
52. Why are enzymes catalytic actions specific to a particular reaction?
53. Describe the catalytic cycle of an enzyme.
54. Which two factors should be at optimal conditions for an enzyme to be most effective?
55. Explain how an enzyme speeds up a specific reaction.
56. What are cofactors? How do they participate in enzymatic reactions?
57. What is a coenzyme? How is it different from a cofactor?
58. What is a chemical inhibitor?
59. Briefly explain how competitive and noncompetitive inhibitors regulate enzymatic activity.
60. Describe how feedback inhibition regulates enzymatic activity.
61. Explain an advantage of feedback inhibition to a cell.