Section 2

Front 1

1. According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

Back 1

C) They can move laterally along the plane of the membrane

Front 2

2. You measure the uptake of a compound into cells and find that in the presence of ATP there is uptake, but in the absence of ATP there is not. What is the best explanation?

Back 2

D) This compound is taken up by active transport

Front 3

3. Which of the following statements is correct about diffusion?

Back 3

B) It is a passive process in which molecules move from a region of higher concentration to one of lower concentration

Front 4

4. Your blood contains the equivalent of 0.15 M NaCl. Distilled water contains the equivalent of 0.0 M NaCl. What will happen if your red blood cells are transferred from your bloodstream into distilled water?

Back 4

B) The blood cells will take up water, swell, and eventually burst

Front 5

5. Solution A is hypotonic in comparison to Solution B. This means that

Back 5

C) Solution A has a lower concentration of dissolved solutes than Solution B

Front 6

6. In what osmotic environment are animal and plant cells the healthiest?

Back 6

C) Animal cells in an isotonic environment; Plant cells in a hypotonic environment

Front 7

7. Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Back 7

E) It is specific for a particular type of molecule

Front 8

8. What is a membrane potential?

Back 8

C) A voltage difference across a membrane due to unequal distribution of charged solutes

Front 9

9. Sucrose is transported into cells along with a hydrogen ion by means of a single membrane protein. This is an example of:

Back 9

C) Cotransport

Front 10

10. A vesicle fuses with a cell membrane, releasing its contents outside of the cell. Which type of transport event is this?

Back 10

A) Exocytosis

Front 11

11. Which term most-precisely describes the cellular process of synthesizing large, complex molecules from smaller, simpler molecules?

Back 11

D) Anabolism

Front 12

12. What is stated by the First Law of Thermodynamics?

Back 12

C) Energy can be transformed into other forms of energy, but energy cannot be created or destroyed

Front 13

13. Which molecule connects anabolism and catabolism in cells by storing energy from catabolic reactions and providing that energy to anabolic reactions?

Back 13

D) ATP

Front 14

14. A chemical reaction that has a positive ΔG is correctly described as

Back 14

C) Endergonic

Front 15

15. Characterize this reaction: Glucose + O2 → CO2 + H2O + energy

Back 15

B) Catabolic; ΔG < 0; Exergonic; NADH intermediate; ATP is produced

Front 16

16. How do enzymes speed up chemical reactions in cells?

Back 16

D) Enzymes lower the activation energy barrier of reactions

Front 17

17. What is the active site of an enzyme?

Back 17

C) The place on the enzyme where the substrate binds

Front 18

18. Iron is found in the active site of many functional enzymes. The iron most likely functions as a(n)

Back 18

B) Cofactor necessary for enzyme activity

Front 19

19. How does a non-competitive inhibitor decrease the rate of an enzyme reaction?

Back 19

B) By changing the shape of the enzyme’s active site

Front 20

20. The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as

Back 20

C) Feedback inhibition

Front 21

21. When a molecule of NAD+ gains an electron as part of a redox reaction, it becomes

Back 21

reduced

Front 22

22. Which of the following statements about NAD+ is false?

Back 22

A) In the absence of NAD+, glycolysis cannot function
B) ***NAD+ has more chemical energy than NADH
C) NAD+ is reduced to NADH during both glycolysis and the Citric Acid Cycle
D) NAD+ can receive electrons for use in oxidative phosphorylation

Front 23

23. The primary role of oxygen in cellular respiration is to:

Back 23

E) Act as an electron acceptor at the end of the electron transport chain

Front 24

24. The ATP made during glycolysis is generated by:

Back 24

D) Substrate-level phosphorylation

Front 25

25. What happens in glycolysis?

Back 25

B) Glucose is split into two pyruvate molecules, creating 2 NADH and 2 ATP

Front 26

26. What happens in the Citric Acid Cycle?

Back 26

C) Acetyl-CoA is converted to 2 CO2, forming 3 NADH, 1 ATP and 1 FADH2

Front 27

27. Describe the flow of electrons during cellular respiration.

Back 27

D) Sugars → NADH → Electron Transport Chain → O2

Front 28

28. The most important function of fermentation is to

Back 28

A) Recycle NADH to NAD+ so that glycolysis can continue

Front 29

29. Organisms that carry out anaerobic respiration

Back 29

D) Use a different electron acceptor than oxygen in the electron transport chain

Front 30

30. When oxygen is released as a result of photosynthesis, it is a by-product of which of the following?

Back 30

B) Splitting of water molecules

Front 31

31. Photosynthesis requires light. Why?

Back 31

C) Light excites electrons in pigments, and these high-energy electrons are used later to reduce CO2, forming sugars

Front 32

32. Why are plants green?

Back 32

B) They absorb mainly blue and red wavelengths of light, but reflect the green wavelengths of light

Front 33

33. What is a photosystem?

Back 33

B) A cluster of pigments and proteins that work together to capture light energy

Front 34

34. In the thylakoid membranes, what is the main role of the pigment molecules in the light harvesting complexes?

Back 34

D) Absorb photons and transfer light energy to the reaction-center chlorophylls

Front 35

35. Oxidation of NADPH occurs during

Back 35

B) Photosynthesis only

Front 36

36. Which two molecules are the products of the light reactions, and where do they go?

Back 36

C) NADPH and ATP; they go to the Calvin cycle

Front 37

37. Both cellular respiration and photosynthesis make use of a hydrogen ion gradient created by an electron transport chain to produce:

Back 37

C) ATP

Front 38

38. Photosynthetic reactions that require the input of CO2 occur in

Back 38

C) The Calvin cycle alone

Front 39

39. What happens in the Calvin cycle of photosynthesis?

Back 39

D) CO2 is fixed and glyceraldehyde-3-phosphate (G3P) is made, using NADPH and ATP

Front 40

40. Describe the flow of electrons during photosynthesis.

Back 40

B) Water → PS2 → Electron Transport Chain → PS1 →NADPH → Sugars