Deck 5: Microbial Metabolism

Question 1

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

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

Answer 1

D

Question 2

What is the purpose of the light-dependent reactions of photosynthesis?

A) production of ATP and NADPH
B) production of oxygen
C) production of ATP and NADH
D) carbon fixation
E) regeneration of NAD⁺

Answer 2

A

Question 3

Which of the following statements concerning cellular metabolism is FALSE?

A) Energy obtained from nutrients or light is stored in the bonds of ATP.
B) Enzymes are used in both catabolic and anabolic reactions.
C) Macromolecules are converted into cell structures via catabolism.
D) The goal of metabolism is reproduction of the organism.
E) ATP is used in the formation of macromolecules.

Answer 3

C

Question 4

Pyruvic acid is a product of

A) the Krebs cycle.
B) fermentation.
C) glycolysis.
D) the Entner-Doudoroff pathway.
E) both glycolysis and the Entner-Doudoroff pathway.

Question 5

Anabolic reactions may be characterized as

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

Question 6

Types of chlorophyll differ in the

A) amount of light they can absorb.
B) amount of ATP they produce.
C) number of electrons they release.
D) amount of oxygen they utilize.
E) wavelengths of light they absorb.

Question 7

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

Question 8

Which of the following statements concerning the Krebs cycle is FALSE?

A) Oxaloacetic acid is regenerated.
B) It is also known as the tricarboxylic acid cycle.
C) Two molecules of acetyl-CoA generate more ATP after two cycles than a single molecule of glucose at the end of glycolysis.
D) The ATP generated is initially GTP.
E) NAD⁺ and FAD are reduced as a result.

Question 9

Which of the following statements concerning glycolysis is TRUE?

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

Question 10

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

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

Question 11

Which of the following statements concerning reduction reactions is FALSE?

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

Question 12

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

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

Question 13

Carbon dioxide is a by-product of which of the following?

A) the Krebs cycle
B) glycolysis
C) chemiosmosis
D) the pentose phosphate pathway
E) electron transport

Question 14

Which of the following produces NADPH?

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

Question 15

All of the following are forms of oxidation EXCEPT

A) loss of an electron.
B) loss of hydrogen atom.
C) a dehydrogenation event.
D) substrate level phosphorylation.
E) gain of an oxygen atom and its electrons.

Question 16

Which of the following types of carrier molecules is NOT found in electron transport chains?

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

Question 17

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

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

Question 18

The molecule that an enzyme acts upon is known as its

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

Question 19

All of the following are associated with chemiosmosis EXCEPT

A) creation of a proton gradient.
B) beta-oxidation.
C) phosphorylation of 34 molecules of ADP.
D) oxidative phosphorylation.
E) ATP synthase.

Question 20

Which of the following statements concerning enzymes is FALSE?

A) They are usually, but not always, proteins.
B) They function best at 37°C.
C) They can be denatured if the pH of their environment is too high or too low.
D) They form a temporary intermediate compound with a substrate.
E) They can be used to catalyze a chemical reaction over and over again.

Question 21

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

A) CO₂
B) ATP
C) RuBP
D) glyceraldehyde 3-phosphate
E) NADPH

Question 22

Beta-oxidation of fatty acids produces a substrate of

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

Question 23

The conversion of amino acids to carbohydrates is an example of

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

Question 24

In which of the following stages of glycolysis is ATP made?

A) energy-investment stage
B) lysis stage
C) energy-conserving stage
D) both the energy-investment and the lysis stages
E) both the lysis and energy-conserving stages

Question 25

When a cell forms an amino acid by adding an amine group derived from ammonia to a precursor metabolite, this process is called

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

Question 26

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

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

Question 27

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

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

Question 28

Hydrolases are generally involved in __________ reactions.

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

Question 29

The metabolic processes called fermentation

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

Question 30

Reactions catalyzed by transferases are

A) catabolic.
B) anabolic.
C) neither anabolic nor catabolic.
D) both anabolic and catabolic.
E) reactions that do not require cofactors.

Question 31

Membranes containing the photosystems necessary for photosynthesis are called

A) thylakoids.
B) grana.
C) stroma.
D) chlorophylls.
E) cytochromes.

Question 32

Where is the most ATP generated for most eukaryotic cells?

A) in the cytoplasmic membrane
B) in the cytosol
C) in the outer membrane of the mitochondria
D) in the mitochondrial matrix
E) on ribosomes

Question 33

Enzymes known as lyases participate in __________ reactions.

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

Question 34

Reactions involving isomerases are

A) anabolic.
B) catabolic.
C) both anabolic and catabolic.
D) neither anabolic nor catabolic.
E) exergonic.

Question 35

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

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

Question 36

Oxidoreductases participate in __________ reactions.

A) catabolic
B) anabolic
C) both anabolic and catabolic
D) neither anabolic nor catabolic
E) energy neutral

Question 37

Chemical reactions that can proceed toward either anabolism or catabolism are called

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

Question 38

The conversion of pyruvic acid to acetyl-CoA can be described as __________, because a molecule of CO₂ is produced as a by-product.

A) decarboxylation
B) amination
C) respiration
D) oxidation
E) phosphorylation

Question 39

Which of the following is associated with the Calvin-Benson cycle?

A) acetyl-CoA
B) TMAO
C) RuBP
D) FADH₂
E) PABA

Question 40

All of the following are aspects of a cell's ability to regulate its metabolism EXCEPT

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

Question 41

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

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

Question 42

Fermentation pathways provide a cell with an alternative way to regenerate NAD⁺ for glycolysis.

Question 43

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

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

Question 44

Ribozymes are enzymes that cleave the subunits of the ribosome.

Question 45

Reactions involving ligases are typically __________ reactions.

A) anabolic
B) catabolic
C) both anabolic and catabolic
D) neither anabolic nor catabolic
E) exergonic

Question 46

The intermediate known as DHAP is formed during the __________ stage(s) of glycolysis.

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

Question 47

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

Question 48

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

Question 49

Glucose enters glycolysis at the __________ stage(s).

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

Question 50

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

Question 51

A __________ reaction is one in which a molecule accepts an electron.

Question 52

Environmental changes can result in the inactivation of enzymes.

Question 53

Reactions that are both catabolic and anabolic are amphibolic.

Question 54

Glucose is used as an energy source only when proteins and fats are not available.

Question 55

ATP is produced by the phosphorylation of __________.

Question 56

Another term for an organic catalyst is a(n) __________.

Question 57

The __________ point of an enzyme is reached when all active sites have bound substrate molecules.

Question 58

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

Question 59

NAD⁺ and NADP⁺ are important examples of both coenzymes and electron carriers.

Question 60

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

Question 61

During electron transport in chloroplast thylakoids, protons are pumped outside the thylakoid into a space called the __________.

Question 62

Electrons are transferred in the Krebs cycle in the form of __________ atoms to NAD+ and FAD.

Question 63

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

Question 64

Enzymes increase the rate of reaction by lowering the __________ energy.

Question 65

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

Question 66

Anaerobic respiration involves the use of molecules other than oxygen as the final electron __________ in an electron transport chain.

Question 67

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

Question 68

During glycolysis, glucose is converted to __________ acid, a molecule that can be used in either fermentation or respiration pathways.

Question 69

Explain why fermentation is a necessary alternative to respiration in many cells.

Question 70

The __________ generate amino acids from carbohydrate precursors and glutamic acid.

Question 71

The purpose of electron transport is to create a proton __________ across a membrane that can then be used to make ATP.

Question 72

Waste products such as sulfur are produced by __________ photosynthetic bacteria as they obtain electrons for noncyclic photophosphorylation.

Question 73

Compare and contrast cyclic and noncyclic photophosphorylation.

Question 74

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

Question 75

Laboratory fermentation tests often include a pH indicator because many bacteria produce __________ as they ferment carbohydrates.