Chapter 10 Microbiology

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15. Photosynthetic organisms serve as the base for most food chains in the biosphere.

True

False

16. Although most metabolic reactions are freely reversible, a few irreversible catabolic steps are bypassed during biosynthesis with special enzymes that catalyze the reverse reaction in order to allow for independent regulation of catabolic and anabolic pathways.

True

False

17. The catabolism of glucose begins with one or more of the glycolytic pathways that yield pyruvate.

True

False

18. In addition to being used in the making of ATP, proton motive force is used directly to power the rotation of bacterial flagella.

True

False

19. Prokaryotes may use several different terminal oxidases for the electron transport system.

True

False

20. An organism may use glycolysis and the pentose phosphate pathway simultaneously.

True

False

21. Fermentation involves the use of pyruvate and/or other organic molecules as electron acceptors.

True

False

22. Bacterial electron transport chains may be comprised of fewer components and have lower P/O ratios than mitochondrial transport chains.

True

False

23. The sum total of all chemical reactions occurring in a cell is called

Anabolism

Catabolism

Metabolism

None of the choices

24. Reduction of nitrate to nitrite by Paracoccus denitrificans is an example of anaerobic respiration.

True

False

25. The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO2 and

Lactate

Isocitric acid

Acetyl-CoA

Succinyl-CoA

26. Fatty acids are metabolized by the __________ pathway.

Alpha-oxidation

Beta-oxidation

Gamma-oxidation

Delta-oxidation

27. Which of the following may be used as sources of energy by chemolithotrophs?

Hydrogen gas

Reduced nitrogen compounds

Reduced sulfur compounds

All of the choices

28. The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhoff pathway in prokaryotes is

2

36

38

85

29. In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.

More

Less

The same amount of

30. All prokaryotic photosynthesizers are anoxygenic.

True

False

31. Which of the following can be used as electron acceptors during anaerobic respiration?

Nitrate

Sulfate

Carbon dioxide

All of the choices

32. The electron transport systems in eukaryotes and prokaryotes use different electron carriers.

True

False

33. Very few gram positive bacteria utilize the Entner-Doudoroff glycolytic pathway.

True

False

34. Metabolic pathways can be either catabolic or anabolic but not both.

True

False

35. In the TCA cycle, two carbons in the form of __________ are added to oxaloacetate at the start of the cycle.

Acetyl-CoA

Ethanol

Carbon dioxide

Methanol

36. All eukaryotic photosynthesizers are oxygenic.

True

False

37. The pentose phosphate pathway produces

CO2

NADPH

Glyceraldehyde 3-phosphate

All of the choices

38. Mitochondrial electron transport takes place

On the outer mitochondrial membrane.

On the inner mitochondrial membrane.

In the fluid matrix of the mitochondria.

On the outer mitochondrial membrane and on the inner mitochondrial membrane

39. The most common pathway for conversion of glucose to pyruvate is

Entner-Doudoroff

Pentose phosphate

Embden-Meyerhoff

Mixed acid fermentation

40. Oxygen is always required for the regeneration of NAD from NADH.

True

False

41. The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O2 is called the

Utilization ratio

Energy yield

P/O ratio

Phosphorylation coefficient

42. The synthesis of ATP from ADP and Pi, when coupled with an exergonic chemical reaction is called __________ phosphorylation.

Chemiosmotic

Oxidative

Substrate level

Conformational change

43. The major function(s) of the TCA cycle is(are)

Energy production

Provision of carbon skeletons for biosynthesis of cell components.

Electron transport.

Energy production and provision of carbon skeletons for biosynthesis of cell components.

44. Differences between mitochondrial and E. coli electron transport chains include the following:

The E. coli chain contains a different array of cytochromes.

The fundamental principles on which they operate are different.

Higher P/O values are observed in E. coli.

The electron transport change does not involve membranes in E. coli.

45. In the process of __________, ATP is synthesized when excited electrons from chlorophyll P700 pass through a series of electron carriers then return to chlorophyll P700.

Photosynthesis

Cyclic photophosphorylation

Acyclic photophosphorylation

Noncyclic photophosphorylation

46. During breakdown of fatty acids, carbons are removed __________ at a time with each turn of the cycle, and two carbon units are released as __________.

One; carbon dioxide

One; methane

Two; acetyl-CoA

Two; ethanol

47. How many molecules of NADPH are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis?

2

3

4

10-12

48. In the TCA cycle, two carbons are removed from citric acid in the form of __________, thereby regenerating oxaloacetate to complete the cycle.

Acetyl-CoA

Ethanol

Carbon dioxide

Methanol

49. In the process of noncyclic photophosphorylation

Water is split to form oxygen gas.

Electrons from water flow through electron transport chains resulting in synthesis of ATPand NADPH.

Photosystems I and II are both required.

All of the choices

50. The net gain of ATP per molecule of glucose metabolized to pyruvate using Entner-Doudoroff pathway is

4

2

1

0

51. Which of the following is NOT true regarding ATP synthases?

They require proton motive force to make ATP.

They span the inner membrane of mitochondria.

The proton flow is outward during ATP synthesis.

The subunits of ATP synthase undergo conformational changes during ATP production.

52. The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is

2

32

38

85

53. The TCA cycle generates all of the following from each acetyl-CoA molecule oxidized except

Three NADH molecules.

Two CO2 molecules.

One FADH2 molecule.

One ATP molecule.

54. Production of ATP using the energy liberated when electrons from reduced chemical bonds are passed through the electron transport system is generally referred to as __________.

Chemiosmotic

Respiration

Substrate-level

Conformation change

55. How many quanta of light are needed to reduce one molecule of carbon dioxide to carbohydrate during photosynthesis?

2

3

4

10-12

56. Some aerobic bacteria lack the Entner-Doudoroff and Embden-Meyerhoff pathways and instead use the pentose phosphate pathway for glycolysis.

True

False

57. In higher eukaryotes, most aerobically generated ATP is produced by

Glycolysis

The TCA cycle

A membrane bound proton translocating ATP synthase during oxidative phosphorylation.

All of these generate equal amounts of ATP.

58. Photosynthetic electron transport in cyanobacteria takes place

On the plasma membrane.

In the chloroplast

In the cytoplasm

On the thylakoid membranes

59. How many molecules of ATP are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis?

2

3

4

10-12

60. In the process of fermentation an organic substrate, such as glucose, is reduced and an intermediate of the pathway, such as pyruvate, is oxidized.

True

False

61. Amino acids are processed first by the removal of the amino group through

Deamination

Trasamination

Phosphorolytic cleavage

Deamination or transamination

62. Nitrification of ammonia occurs when ammonia is first converted to nitrite and then is converted to nitrate by the nitrogen-fixing bacteria.

True

False