Deck 8: An Introduction to Microbial Metabolism: the Chemical Crossroads of Life

Question 1

The most likely place where an exoenzyme participates in a chemical reaction is:

A)mitochondria.
B)within the cell membrane.
C)lysosomes.
D)cytoplasm.
E)outside of the cell.

Answer 1

E

Question 2

All of the following are exoenzymes, except:

A)ATP synthase.
B)streptokinase.
C)penicillinase.
D)collagenase.
E)elastase.

Answer 2

A

Question 3

The breakdown of peptidoglycan to N-acetylmuramic acid, N-acetylglucosamine and peptides is an example of:

A)anabolism.
B)catabolism.
C)phosphorylation.
D)fermentation.
E)biosynthesis.

Answer 3

B

Question 4

Enzymes that are produced only when substrate is present are termed:

A)exoenzymes.
B)endoenzymes.
C)constitutive enzymes.
D)induced enzymes.
E)conjugated enzymes.

Question 5

Enzymes that catalyze removing electrons from one substrate and adding electrons to another are called:

A)phosphotransferases.
B)oxidoreductases.
C)decarboxylases.
D)aminotransferases.
E)ligases.

Question 6

Exergonic reactions:

A)include synthesis of large carbohydrates.
B)only occur in heterotrophs.
C)occur during aerobic cellular respiration.
D)do not occur in anaerobic cellular respiration.
E)occur when ADP binds to inorganic phosphate to form ATP.

Question 7

Enzymes are:

A)broken down in reactions that require energy input.
B)proteins that function as catalysts.
C)electron carrier molecules.
D)not needed for catabolic reactions.
E)All of the choices are correct.

Question 8

In addition to electrons, which of the following is also involved in electron transfer?

A)ADP
B)glucose
C)carbon
D)hydrogen protons
E)carbon dioxide

Question 9

When enzyme action stops due to a buildup of end product this control is called:

A)negative feedback.
B)competitive inhibition.
C)enzyme induction.
D)enzyme repression.
E)None of the choices are correct.

Question 10

All of the chemical reactions of the cell are called:

A)catabolism.
B)redox reactions.
C)phosphorylation.
D)metabolism.
E)cellular respiration.

Question 11

The step involving ATP, hexokinase, and the phosphorylation of glucose to glucose-6-phosphate is:

A)the final step of the Krebs cycle.
B)the first redox reaction of the electron transport system.
C)an example of oxidative phosphorylation.
D)an example of substrate-level phosphorylation.
E)an example of photophosphorylation.

Question 12

Enzymes that can function at boiling water temperatures or other harsh conditions would be termed:

A)denatured.
B)ribozymes.
C)abzymes.
D)exoenzymes.
E)extremozymes.

Question 13

Formation of peptide bonds between amino acids to build a polypeptide would be called:

A)anabolism.
B)phosphorylation.
C)fermentation.
D)exergonic.
E)glycolysis.

Question 14

A holoenzyme is a combination of a protein and one or more substances called:

A)substrates.
B)apoenzymes.
C)catalysts.
D)cofactors.
E)None of the choices are correct.

Question 15

All of the following pertain to glycolysis, except it:

A)occurs without oxygen.
B)ends with formation of pyruvic acid.
C)occurs during fermentation.
D)degrades glucose to CO₂ and H₂O.
E)involves reduction of NAD.

Question 16

An apoenzyme:

A)is part of a simple enzyme.
B)is also called a coenzyme.
C)contains the active site.
D)is often an inorganic metal ion.
E)is an RNA molecule.

Question 17

The formation of citric acid from oxaloacetic acid and an acetyl group begins:

A)glycolysis.
B)electron transport system.
C)Krebs cycle.
D)fermentation.
E)oxidative phosphorylation.

Question 18

In the cell, energy released by electrons is often used to phosphorylate:

A)ATP.
B)ADP.
C)pyruvic acid.
D)oxygen.
E)NAD.

Question 19

Important components of coenzymes are:

A)vitamins.
B)metallic ions.
C)active sites.
D)substrates.
E)ribozymes.

Question 20

Most electron carriers are:

A)coenzymes.
B)enzymes.
C)hydrogens.
D)inorganic phosphate.
E)All of the choices are correct.

Question 21

Fatty acids can be metabolized by entering:

A)glycolysis.
B)the TCA cycle.
C)the electron transport chain.
D)the phosphogluconate pathway.
E)lactic acid fermentation.

Question 22

In bacterial cells, the electron transport system is located in the:

A)cell membrane.
B)mitochondria.
C)chloroplasts.
D)ribosomes.
E)cytoplasm.

Question 23

Anaerobic cellular respiration:

A)is also called fermentation.
B)only involves glycolysis.
C)does not generate ATP.
D)utilizes an electron transport system.
E)uses the same final electron acceptors as aerobic respiration.

Question 24

Mixed acid fermentation:

A)produces butyric acid.
B)occurs in all bacteria.
C)produces acids plus CO₂ and H₂ gases.
D)is seen in Streptococcus and Lactobacillus.
E)also produces ethanol.

Question 25

When glucose is broken down by glycolysis during bacterial fermentation, how many ATP are generated?

A)2 ATP
B)3 ATP
C)24 ATP
D)36 ATP
E)38 ATP

Question 26

The process of alcoholic fermentation produces:

A)alcohol only.
B)alcohol and oxygen.
C)alcohol and carbon dioxide.
D)carbon dioxide and yeast.
E)yeast and oxygen.

Question 27

During which of the phases of cellular respiration is the majority of ATP formed?

A)electron transport
B)Krebs cycle
C)glycolysis
D)processing of pyruvic acid for the Krebs cycle
E)All phases produce the same number of ATP molecules.

Question 28

Which of the following is NOT involved in the step that occurs between glycolysis and the TCA cycle?

A)reduction of NAD
B)decarboxylation of pyruvic acid
C)coenzyme A attaches to an acetyl group
D)dehydrogenation of pyruvic acid
E)pyruvic acid accepts electrons from NADH

Question 29

In anaerobic respiration, all of the following can serve as the final electron acceptor, except:

A)nitrate.
B)oxygen.
C)sulfate.
D)nitrite.
E)None of the choices are correct.

Question 30

In which pathway is the most NADH generated?

A)electron transport system
B)Krebs cycle
C)glycolysis
D)alcoholic fermentation
E)mixed acid fermentation

Question 31

The reactions of fermentation function to produce _____ molecules for use in glycolysis.

A)pyruvic acid
B)ATP
C)NAD
D)NADH
E)glucose

Question 32

Cyanide will cause rapid death in humans because it:

A)stops glycolysis.
B)stops the TCA cycle from turning.
C)stops the electron transport chain at coenzyme Q.
D)blocks cytochrome c oxidase.
E)inhibits the ATP synthase.

Question 33

Enteric bacteria commonly occupy the human intestine and primarily produce:

A)CO₂ and H₂gases.
B)methane gas.
C)lactic acid.
D)alcohol.
E)butyric acid.

Question 34

Each NADH that enters the electron transport system gives rise to _____ ATP.

A)2
B)3
C)24
D)36
E)38

Question 35

During aerobic cellular respiration, the final electron acceptor is:

A)pyruvic acid.
B)oxygen.
C)nitrate.
D)cytochrome c.
E)FAD.

Question 36

As the electron transport carriers shuttle electrons, they actively pump _____ into the outer membrane compartment setting up a concentration gradient called the proton motive force.

A)ATP
B)phosphate
C)hydrogen ions
D)oxygen
E)NADH

Question 37

Why is cyanide harmless to some bacteria?

A)They break down the cyanide before it enters the electron transport chain.
B)They shut off the TCA cycle until the cyanide is diluted out of the cell.
C)They lack cytochrome c oxidase.
D)They don't allow cyanide to cross their cell wall.
E)Cyanide is deadly for all bacteria.

Question 38

Enzymes that are regularly found in a cell are termed:

A)exoenzymes.
B)endoenzymes.
C)constitutive enzymes.
D)induced enzymes.
E)conjugated enzymes.

Question 39

Each FADH₂ that enters the electron transport system gives rise to _____ ATP.

A)2
B)3
C)24
D)36
E)38

Question 40

In bacterial cells, when glucose is completely oxidized by all the pathways of aerobic cellular respiration, how many ATP are generated?

A)2 ATP
B)3 ATP
C)24 ATP
D)36 ATP
E)38 ATP

Question 41

Photosynthesis is responsible for producing >50% of Earth's oxygen.During photosynthesis inorganic __ is fixed into organic compounds like___ without the help of sunlight.

A)H₂O, Oxygen
B)CO₂, C₆H₁₂O₆
C)H₂O, C₆H₁₂O₆
D)CO₂, Oxygen
E)All of the choices are correct

Question 42

Only yeast produces alcohol as a fermentation product.

Question 43

When amino acids are deaminated, they can be used as a source of:

A)glucose.
B)fat.
C)vitamins.
D)minerals.
E)carbon.

Question 44

In eukaryotes, the Krebs cycle takes place:

A)in the nucleus.
B)in the endoplasmic reticulum.
C)in the cell membrane.
D)in the mitochondria.
E)in the cytoplasm.

Question 45

Building block molecules for biosynthetic pathways come from the cell's catabolic pathways and from the environment.

Question 46

ATP molecules are catalysts that lower the activation energy needed to initiate a reaction.

Question 47

Glyceraldehyde-3-phosphate is an intermediary of glycolysis that can also be utilized in biosynthetic pathways.

Question 48

Hydrolysis reactions are catabolic reactions that use water to split the reactant into smaller subunits.

Question 49

Metabolic pathways that are bidirectional are called _____ pathways.

Question 50

Facultative anaerobes can utilize aerobic cellular respiration when oxygen is present and fermentation when oxygen is in low supply.

Question 51

The cell's metabolic reactions involve the participation of _____ that lower the activation energy needed for the initiation of a reaction.

Question 52

ATP synthase is a complex enzyme needed for oxidative phosphorylation.

Question 53

_____ reactions are anabolic reactions involving ligases for synthesis and the release of one water molecule for each bond formed.

Question 54

Each FADH₂ from the Kerbs cycle enters the electron transport system and gives rise to _____ ATP's.

Question 55

The redox carriers of the electron transport chain that have a tightly bound metal atom responsible for accepting and donating electrons are the _____.

Question 56

In the eukaryote, the respiratory chain is located in the ___, whereas the majority of ATP is produced by the respiratory chain in the _______ of a prokaryote.

A)Lysosome, flagella
B)Golgi body, mitochondria
C)Mitochondria, outer membrane space
D)Mitochondria, ribosome
E)SER, nucleus

Question 57

FAD, NADP, NAD, and coenzyme A are all _____ carriers.

Question 58

In eukaryotes, glycolysis takes place:

A)in the mitochondria.
B)in the endoplasmic reticulum.
C)in the cell membrane.
D)in the nucleus.
E)in the cytoplasm.

Question 59

All aerobic bacterial species have identical electron acceptors in their electron transport systems.

Question 60

ATP is composed of deoxyribose, adenine, and 3-phosphate groups.

Question 61

Describe ATP synthase with regard to: a) its molecular structure, b) its cell location and function, and c) its specific activity in coupling electron transport to ATP production.

Question 62

Discuss the electron transport chain with regard to: a) its composition, b) its function in cellular respiration, c) its location in eukaryotes versus prokaryotes, and d) role in chemiosmosis.

Question 63

Discuss denaturation with regard to: a) what occurs in the process, b) conditions that cause it, and c) the specific affect on an enzyme.

Question 64

_____ testing can differentiate between bacterial species fermentation that produce mixed acids or 2, 3 butanediol.

Question 65

_____ enzymes have an active site, and an additional regulatory site for non-substrate attachment.

Question 66

Amination is the addition of a/an _____ group to a carbon skeleton.

Question 67

Briefly discuss the main events of light dependent photosynthesis including what is required for the desired product(s) to form.

Question 68

Compare and contrast negative feedback control of an enzyme versus enzyme repression.

Question 69

Compare and contrast aerobic respiration, anaerobic respiration, and fermentation.