Deck 5: Microbial Metabolism

Question 1

Which of the following can be the final electron acceptor in anaerobic respiration in bacteria?

A) pyruvic acid only
B) sulfate only
C) nitrate only
D) both nitrate and sulfate
E) nitrate, pyruvic acid, and sulfate

Answer 1

D

Question 2

Which of the following is/are common to chemiosmosis and the light -dependent reactions of photosynthesis?

A) reduction of NADP+ only
B) a proton gradient only
C) electron transport only
D) both electron transport and a proton gradient
E) electron transport, a proton gradient, and reduction of NADP +

Answer 2

D

Question 3

Which of the following is a by-product of the catabolism of proteins?

A) carbon dioxide
B) lactic acid
C) ammonia
D) proteases
E) acetyl-CoA

Answer 3

C

Question 4

Changes in can be useful in analyzing microbesʹ ability to ferment carbohydrates.

A) pH
B) osmotic pressure
C) temperature
D) oxygen use
E) smell

Question 5

Which of the following is a fermentation product useful in the manufacture of cheese?

A) lactic acid
B) ethanol
C) ammonia
D) pyruvic acid
E) acetic acid

Question 6

Anabolic reactions may be characterized as

A) breaking large molecules into smaller molecules.
B) breaking large molecules into smaller molecules to produce ATP.
C) exergonic.
D) producing ATP.
E) forming large molecules from smaller molecules.

Question 7

The catalytic component of a ribozyme is

A) an apoenzyme.
B) a cofactor.
C) RNA.
D) a coenzyme.
E) FADH.

Question 8

A catabolic process which occurs in eukaryotic mitochondria is

A) the Calvin-Benson cycle.
B) deamination.
C) the Entner-Doudoroff pathway.
D) beta-oxidation.
E) fermentation.

Question 9

Which of the following statements concerning glycolysis is TRUE?

A) Glycolysis both requires the input of ATP and produces ATP.
B) Glycolysis is an alternative to fermentation.
C) Glycolysis occurs in the cell membranes of bacteria.
D) Ribulose 5-phosphate is an intermediate of glycolysis.
E) Glycolysis produces ATP by oxidative phosphorylation.

Question 10

Which of the following statements concerning reduction reactions is FALSE?

A) An electron acceptor gains an electron.
B) They frequently involve electron carrier molecules.
C) They are coupled with oxidation reactions.
D) A molecule gains a hydrogen atom.
E) An electron acceptor becomes more positively charged.

Question 11

NAD (nicotinamide adenine dinucleotide) is required for many reactions.

A) oxidation-reduction
B) catabolic
C) ribozyme
D) phosphorylation
E) transfer

Question 12

Which of the following statements is MOST accurate concerning metabolism?

A) Metabolism is the production and expenditure of chemical energy.
B) Metabolism is the assembly of small molecules into macromolecules.
C) Metabolism is the digestion of nutrients to release energy.
D) Metabolism is all the chemical reactions of an organism, both anabolic and catabolic.
E) Metabolism is the assembly of macromolecules into cellular structures.

Question 13

The molecule that an enzyme acts upon is known as its

A) holoenzyme.
B) catalyst.
C) coenzyme.
D) substrate.
E) apoenzyme.

Question 14

Which of the following processes utilize inorganic phosphate?

A) oxidative phosphorylation
B) photophosphorylation
C) substrate-level phosphorylation
D) both photophosphorylation and substrate-level phosphorylation
E) both photophosphorylation and oxidative phosphorylation

Question 15

The habitat of a photosynthetic organism is largely determined by the

A) amount of available hydrogen.
B) chlorophylls it produces.
C) carbohydrates it can metabolize.
D) products of its light-independent reactions.
E) amount of available oxygen.

Question 16

How many ATP molecules can theoretically be produced from the NADH generated by the catabolism of a molecule of glucose during aerobic respiration?

A) 4
B) 30
C) 36
D) 38
E) 34

Question 17

Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as

A) feedback inhibition.
B) competitive inhibition.
C) allosteric inhibition.
D) noncompetitive inhibition.
E) excitatory allosteric control.

Question 18

Heme complexed with iron is found in of the electron transport chain.

A) ubiquinones
B) cytochromes
C) metal-containing proteins
D) ribozymes
E) flavoproteins

Question 19

Which of the following produces NADPH?

A) the Entner-Doudoroff pathway only
B) the Embden-Meyerhof pathway only
C) the pentose phosphate pathway only
D) both the Embden-Meyerhof and Entner-Doudoroff pathways
E) both the pentose phosphate and Entner-Doudoroff pathways

Question 20

Which of the following is required for holoenzyme function?

A) a substrate
B) an allosteric inhibitor
C) a coenzyme
D) a protein cofactor
E) an activator

Question 21

In reactions catalyzed by oxidoreductases an electron donor is

A) unaltered.
B) oxidized.
C) synthesized.
D) reduced.
E) degraded.

Question 22

The metabolic processes called fermentation

A) are alternatives for the pentose phosphate pathway.
B) produce substrates for the Krebs cycle.
C) use an organic molecule as a final electron acceptor.
D) produce substrates for glycolysis.
E) occur only when oxygen is readily available.

Question 23

Isomerases catalyze reactions in which

A) biomolecules are oxidized or reduced.
B) biomolecules are assembled from smaller molecules.
C) biomolecules are broken down into their component parts.
D) atoms in biomolecules are rearranged.
E) groups are transferred from one molecule to another.

Question 24

Oxygenic photosynthesis requires

A) photosystem II.
B) the pentose phosphate pathway.
C) substrate-level phosphorylation.
D) the Entner-Doudoroff pathway.
E) glycolysis.

Question 25

Beta-oxidation produces a substrate of the

A) Entner-Doudoroff pathway.
B) Calvin-Benson cycle.
C) pentose phosphate pathway.
D) Krebs cycle.
E) Embden-Meyerhof pathway.

Question 26

Photosystems are assembled in

A) cristae.
B) stroma.
C) thylakoids.
D) grana.
E) cytoplasm.

Question 27

Which of the following is TRUE concerning the structure and function of enzymes?

A) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
B) All enzymes bind cofactors necessary for their function.
C) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme.
D) An apoenzyme is a combination of a cofactor bound to a holoenzyme.
E) Enzymes can function at a wide range of pH.

Question 28

If a cell reverses the process of beta-oxidation, which of the following molecules will it make?

A) nucleotides
B) amino acids
C) starch
D) glycerol
E) fatty acids

Question 29

During the synthesis of acetyl-CoA from pyruvic acid, is produced.

A) H2O
B) FADH2
C) NADH
D) acetic acid
E) ATP

Question 30

All of the following are ways in which cells regulate metabolism EXCEPT

A) isolation of various enzymes within membranous organelles.
B) synthesis of a catabolic enzyme only when its substrate is available.
C) use of the same coenzymes for anabolic and catabolic reactions that share substrate molecules.
D) feedback inhibition by end products.
E) synthesis or degradation of membrane transport proteins.

Question 31

What is the major product of the Calvin-Benson cycle that can then be used to form glucose?

A) ribulose bisphosphate (RuBP)
B) adenosine triphosphate (ATP)
C) NADPH
D) glyceraldehyde 3-phosphate (G3P)
E) carbon dioxide (CO2)

Question 32

Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore, it is pathway.

A) a reductive
B) an oxidative
C) an exergonic
D) an endergonic
E) neither an exergonic nor an endergonic

Question 33

The process of produces amino acids from precursor metabolites and ammonia.

A) transamination
B) deamination
C) polymerization
D) reduction
E) amination

Question 34

The assembly of carbon dioxide and water into carbohydrates occurs in the process known as

A) photosynthesis.
B) chemiosmosis.
C) gluconeogenesis.
D) fermentation.
E) oxidation.

Question 35

Chemical reactions that are reversible, proceeding anabolically or catabolically, are called

A) glycolytic.
B) synthetic.
C) cyclic.
D) light-independent.
E) amphibolic.

Question 36

In aerobic non-photosynthetic organisms, the majority of ATP is generated by

A) glycolysis reactions.
B) oxidation-reduction reactions.
C) substrate-level phosphorylation.
D) catabolic reactions.
E) the Calvin-Benson cycle.

Question 37

Many metabolites for anabolic pathways are produced by the pathway.

A) pentose-phosphate
B) Entner-Doudoroff
C) beta-oxidation
D) glycolytic
E) chemiosmosis

Question 38

The conversion of amino acids to carbohydrates is an example of

A) beta-oxidation.
B) gluconeogenesis.
C) substrate-level phosphorylation.
D) amination.
E) electron transport.

Question 39

Hydrolases are generally involved in reactions.

A) neither anabolic nor catabolic
B) both anabolic and catabolic
C) anabolic
D) catabolic
E) oxidation-reduction

Question 40

Which of the following is the final electron acceptor in aerobic respiration?

A) acetic acid
B) nitrate
C) carbonate
D) oxygen
E) sulfate

Question 41

The arrow indicates the only protein component of this complex. This illustration represents a(n)

A) holoenzyme.
B) ubiquinone.
C) ribozyme.
D) coenzyme.
E) apoenzyme.

Question 42

Ribozymes are enzymes that cleave the subunits of the ribosome.

Question 43

Non-cyclic photophosphorylation requires photosystem II.

Question 44

Gluconeogenesis reactions are generally highly endergonic.

Question 45

As the concentration of substrate increases, the activity of the enzyme decreases.

Question 46

Glycolysis begins with a(n) stage(s).

A) energy-conservation
B) energy-investment
C) lysis
D) lysis and energy-conservation
E) energy-investment and conservation

Question 47

Protein catabolism for prokaryotes starts extracellularly.

Question 48

The bonds between glycerol and fatty acids are broken by (ligase/lipase/lyase) enzymes.

Question 49

Which of the following products of glucose catabolism is a substrate for fatty acid synthesis?

A) phosphoglyceric acid
B) pyruvic acid
C) acetyl-CoA
D) succinyl-CoA
E) oxaloacetate

Question 50

A(n) (oxidation/reduction/transport) reaction is one in which a molecule accepts an electron.

Question 51

Substrate-level phosphorylation occurs during the stage(s) of glycolysis.

A) lysis
B) energy-investment
C) energy-conservation
D) energy-investment and energy-conservation
E) energy-investment, lysis, and energy-conservation

Question 52

Beta oxidation of fatty acids produces substrates for the (Calvin-Benson/Entner-Doudoroff/Krebs) cycle.

Question 53

Identify the processes of glucose metabolism represented in Figure 5 -1.

A) A = glycolysis, B = fermentation, C = Krebs cycle, D = electron transport chain.
B) A = fermentation, B = glycolysis, C = Krebs cycle, D = electron transport chain
C) A = glycolysis, B = Krebs cycle, C = electron transport chain, D = fermentation.
D) A = electron transport chain, B = Krebs cycle, C = glycolysis, D = fermentation
E) A = glycolysis, B = Krebs cycle, C = fermentation, D = electron transport chain

Question 54

Essential amino acids are amino acids that cannot be synthesized by an organism and so must be provided as nutrients.

Question 55

Changes in temperature or pH can cause enzymes to lose activity. What is a common feature of these two effects?

A) Temperature and pH affect the rate of substrate binding.
B) Temperature and pH change the ionization state of cofactors.
C) Temperature and pH both induce an enzyme to lose its precise three-dimensional shape.
D) Temperature and pH change the activation energy of the reaction.
E) There is no common mechanism of temperature and pH effects on enzyme activity.

Question 56

The pentose phosphate pathway generates all the necessary precursors for nucleotide biosynthesis.

Question 57

The ability to utilize different metabolites for cellular respiration is one method for identifying bacteria.

Question 58

The production of NADH takes place during the stage(s) of glycolysis.

A) energy-investment
B) energy-conservation
C) lysis
D) lysis and energy-investment
E) energy-investment and energy-conservation

Question 59

Synthesis of the precursors of purines and pyrimidines requires transamination of ribose-5-phosphate.

Question 60

During chemiosmosis, electrons are pumped across a membrane to produce ATP.

Question 61

Anaerobic respiration involves the use of molecules other than oxygen as the final electron (acceptor/donor) in an electron transport chain.

Question 62

Explain why the ATP yield from processes such as cellular respiration is generally given as a theoretical number.

Question 63

Enzymes increase the rate of reaction by lowering the (activation/reaction/substrate) energy.

Question 64

The majority of the energy captured in the Krebs cycle is in the form of (ATP/FADH2/NADH).

Question 65

A (photosystem/thylakoid/chloroplast) is a collection of pigments such as chlorophyll that are used to absorb light in the light-dependent reactions of photosynthesis.

Question 66

Waste products such as sulfur are produced by (oxygenic/anoxygenic/aerobic) photosynthetic bacteria as they obtain electrons for noncyclic photophosphorylation.

Question 67

During glycolysis, glucose is converted to (pyruvic/acetic/lactic) acid, a molecule that can be used in either fermentation or respiration pathways.

Question 68

Describe the mechanism of feedback inhibition and the role this process plays in controlling enzyme activity.

Question 69

Only Photosystem I is required for (cyclic/noncyclic) photophosphorylation to occur.

Question 70

The (activation/inhibition/saturation) point of an enzyme is reached when all active sites have bound substrate molecules.

Question 71

The purpose of electron transport is to create a proton (concentration/gradient/pump) across a membrane for the process of chemiosmosis.

Question 72

Laboratory fermentation tests often include a pH indicator because many bacteria produce (hydroxyls/bases/acids) as they ferment carbohydrates.

Question 73

The discussion of carbohydrate catabolism includes some of the many metabolic variations microbes are capable of. Using the information in the following table, devise a set of biochemical tests to identify the bacteria in this example Assume you can detect various organic compounds. Prepare a dichotomous key of your identification scheme.

Question 74

The (transferases/transaminases/deaminases) generate amino acids from carbohydrate precursors and glutamic acid.

Question 75

When a noncompetitive inhibitor molecule binds to an (active/allosteric) site on an enzyme, the shape of the active site changes so that the substrate molecules can no longer bind.

Question 76

Compare and contrast cyclic and noncyclic photophosphorylation.

Question 77

Discuss the interrelationships between anabolic and catabolic pathways. Provide specific examples in your answer.

Question 78

Significant amounts of the NADPH required for the Calvin-Benson cycle are produced during the (cyclic/noncyclic) photophosphorylation reactions of photosynthesis.