Question 1

An atom that has a lower affinity for electrons than another is ________ than the other.

Accepted Answer

A)  more electronegative 
B)  less electronegative 
C)  equally electronegative 
D)  more electropositive 
E)  less electropositive 
A)  more electronegative 
B)  less electronegative 
C)  equally electronegative 
D)  more electropositive 
E)  less electropositive A

Question 2

Coenzymes are derivatives of

Accepted Answer

A)  minerals. 
B)  proteins. 
C)  lipids. 
D)  vitamins. 
E)  enzymes. 
A)  minerals. 
B)  proteins. 
C)  lipids. 
D)  vitamins. 
E)  enzymes. D

Question 3

Which of the following is NOT common to aerobic respiration, anaerobic respiration, AND fermentation?

Accepted Answer

A)  Breakdown of glucose 
B)  Generation of ATP 
C)  Electron transport chain 
D)  Reduction of NAD 
E)  Production of pyruvate 
A)  Breakdown of glucose 
B)  Generation of ATP 
C)  Electron transport chain 
D)  Reduction of NAD 
E)  Production of pyruvate C

Question 4

Why would a cell ferment rather than respire?

Accepted Answer

A)  There's no oxygen present, and it cannot respire anaerobically. 
B)  It lacks the ability to respire (i.e. no electron transport chain). 
C)  There is no oxygen present and it cannot use anaerobic respiration OR it lacks the ability to respire (i.e., no electron transport chain). 
D)  More ATP is produced for the cell by fermentation than by aerobic respiration. 
E)  There is too much oxygen available and fermentation is a safer alternative. 
A)  There's no oxygen present, and it cannot respire anaerobically. 
B)  It lacks the ability to respire (i.e. no electron transport chain). 
C)  There is no oxygen present and it cannot use anaerobic respiration OR it lacks the ability to respire (i.e., no electron transport chain). 
D)  More ATP is produced for the cell by fermentation than by aerobic respiration. 
E)  There is too much oxygen available and fermentation is a safer alternative.

Question 5

Which is True of competitive inhibition?

Accepted Answer

A)  It involves an allosteric enzyme. 
B)  Substrate and inhibitor bind to different active sites. 
C)  A sulfa antibiotic is a competitive inhibitor. 
D)  Mercury is a competitive inhibitor. 
E)  Inhibitor permanently changes active site shape. 
A)  It involves an allosteric enzyme. 
B)  Substrate and inhibitor bind to different active sites. 
C)  A sulfa antibiotic is a competitive inhibitor. 
D)  Mercury is a competitive inhibitor. 
E)  Inhibitor permanently changes active site shape.

Question 6

Heart muscle is damaged after a heart attack (MI) because blood flow to the heart is stopped. A researcher injected cyanobacteria into the damaged hearts of test animals that has been given MIs. The animals' conditions improved after the procedure, but not significantly. The researcher repeated the experiment, this time illuminating the cyanobacteria with high intensity light after injecting the cells into the damaged hearts. Now the animals did much better, recovering well from their heart attacks. Which of the following explains this outcome?

Accepted Answer

A)  Cyanobacteria have the capacity to carry blood. Illuminating the cells increases their ability to transport blood into the damage heart muscle. 
B)  Cyanobacteria produce alcohol through photosynthesis, and this stimulates the heart cells. Illuminating the bacteria increases this reaction. 
C)  Illuminated cyanobacteria multiply rapidly; the expanding mass of cells dilates blood vessels to the heart, bringing more nutrients and oxygen to the heart cells. 
D)  Illuminated cyanobacteria produce carbon dioxide by photosynthesis. Illumination increases the amount of released CO₂ that the heart cells then use for anaerobic respiration. 
E)  Cyanobacteria produce oxygen by photosynthesis. Illuminating the cells increases amount of O₂ released that is then used by heart cells for aerobic respiration. 
A)  Cyanobacteria have the capacity to carry blood. Illuminating the cells increases their ability to transport blood into the damage heart muscle. 
B)  Cyanobacteria produce alcohol through photosynthesis, and this stimulates the heart cells. Illuminating the bacteria increases this reaction. 
C)  Illuminated cyanobacteria multiply rapidly; the expanding mass of cells dilates blood vessels to the heart, bringing more nutrients and oxygen to the heart cells. 
D)  Illuminated cyanobacteria produce carbon dioxide by photosynthesis. Illumination increases the amount of released CO₂ that the heart cells then use for anaerobic respiration. 
E)  Cyanobacteria produce oxygen by photosynthesis. Illuminating the cells increases amount of O₂ released that is then used by heart cells for aerobic respiration.

Question 7

NAD in its reduced form is symbolized as

Accepted Answer

A)  NADH. 
B)  NAD. 
C)  NAD−. 
D)  NADP. 
E)  NADP⁺. 
A)  NADH. 
B)  NAD. 
C)  NAD−. 
D)  NADP. 
E)  NADP⁺.

Question 8

Which of the following produces the most precursor metabolites?

Accepted Answer

A)  Fermentation 
B)  TCA cycle 
C)  Pentose phosphate pathway 
D)  Glycolysis 
E)  Transition step 
A)  Fermentation 
B)  TCA cycle 
C)  Pentose phosphate pathway 
D)  Glycolysis 
E)  Transition step

Question 9

Allosteric enzymes

Accepted Answer

A)  may bind two substrates at the same time. 
B)  are used to bind to other enzymes. 
C)  have an additional binding site that is involved in regulating enzyme activity. 
D)  are twice as fast as single-site enzymes. 
E)  have an additional binding site that is never involved in regulating enzyme activity. 
A)  may bind two substrates at the same time. 
B)  are used to bind to other enzymes. 
C)  have an additional binding site that is involved in regulating enzyme activity. 
D)  are twice as fast as single-site enzymes. 
E)  have an additional binding site that is never involved in regulating enzyme activity.

Question 10

How would cellulose-degrading bacteria in the rumen (stomachs) of a cow benefit the animal?

Accepted Answer

A)  The bacteria would produce, secrete, and incorporate organic molecules as they obtain energy from the cellulose in grass and replicate. The cow could then digest both the secreted organic molecules AND the bacteria that synthesized them. 
B)  The bacteria would produce sugars as they digested the cellulose. These sugars would be given off to the cow as a symbiotic relationship in exchange for the protected location of the stomachs of the cow for the bacteria to grow and replicate in. 
C)  They wouldn't benefit the animal - they would replicate and cause disease in the animal, leading to its death. 
D)  They wouldn't benefit the animal but they would benefit the other bacteria within the animal. This is why cows must have food sources other than grass in order to survive. 
E)  They are needed to break down endospores of potential pathogens that are certain to cause illness or even death in the cow if it consumes them when it eats grass. 
A)  The bacteria would produce, secrete, and incorporate organic molecules as they obtain energy from the cellulose in grass and replicate. The cow could then digest both the secreted organic molecules AND the bacteria that synthesized them. 
B)  The bacteria would produce sugars as they digested the cellulose. These sugars would be given off to the cow as a symbiotic relationship in exchange for the protected location of the stomachs of the cow for the bacteria to grow and replicate in. 
C)  They wouldn't benefit the animal - they would replicate and cause disease in the animal, leading to its death. 
D)  They wouldn't benefit the animal but they would benefit the other bacteria within the animal. This is why cows must have food sources other than grass in order to survive. 
E)  They are needed to break down endospores of potential pathogens that are certain to cause illness or even death in the cow if it consumes them when it eats grass.

Question 11

The small, non-protein molecules that can be readily separated from an enzyme and are responsible for transfer of atoms from one molecule to another are referred to as

Accepted Answer

A)  vitamins. 
B)  coenzymes. 
C)  enzymes. 
D)  hormones. 
E)  active sites. 
A)  vitamins. 
B)  coenzymes. 
C)  enzymes. 
D)  hormones. 
E)  active sites.

Question 12

Why was it necessary for the lab to inoculate a sample of the incubated tetrathionate broth onto a medium selective for Salmonella?

Accepted Answer

A)  To confirm that the bacteria in the broth is Salmonella and not another bacterial species. 
B)  To confirm that the bacteria in the broth is E. coli and not another bacterial species. 
C)  To check whether the Salmonella has the ability to form endospores. 
D)  To confirm that Salmonella is a bacterium and not a virus or protozoan. 
E)  To confirm that Salmonella is a facultative anaerobe and not an obligate acidophile. 
A)  To confirm that the bacteria in the broth is Salmonella and not another bacterial species. 
B)  To confirm that the bacteria in the broth is E. coli and not another bacterial species. 
C)  To check whether the Salmonella has the ability to form endospores. 
D)  To confirm that Salmonella is a bacterium and not a virus or protozoan. 
E)  To confirm that Salmonella is a facultative anaerobe and not an obligate acidophile.

Question 13

Enzymes are changed by the reaction as they raise the activation energy.

Accepted Answer

A) True 
 B)False

Question 14

Cells degrade sugar largely to

Accepted Answer

A)  gain energy. 
B)  use energy. 
C)  convert fat to energy. 
D)  use coenzymes. 
E)  generate pyruvate. 
A)  gain energy. 
B)  use energy. 
C)  convert fat to energy. 
D)  use coenzymes. 
E)  generate pyruvate.

Question 15

Both glycolysis and the pentose phosphate pathway oxidize glucose to pyruvate.

Accepted Answer

A) True 
 B)False

Question 16

Mercury in mercurochrome inhibits growth

Accepted Answer

A)  through competitive inhibition. 
B)  through a reversible action. 
C)  by oxidizing the sulfhydryl groups in cysteine. 
D)  by changing the shape of proteins. 
E)  by oxidizing the sulfhydryl groups in cysteine AND by changing the shape of proteins. 
A)  through competitive inhibition. 
B)  through a reversible action. 
C)  by oxidizing the sulfhydryl groups in cysteine. 
D)  by changing the shape of proteins. 
E)  by oxidizing the sulfhydryl groups in cysteine AND by changing the shape of proteins.

Question 17

Tetrathionate is an oxidized form of sulfur that can act as a terminal electron acceptor. What does the fact that S. enterica can grow in this medium this tell you about this organism?

Accepted Answer

A)  It is an obligate aerobe. 
B)  It is an obligate anaerobe. 
C)  It is a facultative anaerobe. 
D)  It is Gram negative. 
E)  It has a capsule. 
A)  It is an obligate aerobe. 
B)  It is an obligate anaerobe. 
C)  It is a facultative anaerobe. 
D)  It is Gram negative. 
E)  It has a capsule.

Question 18

Degradation of fats as an energy source involves all of the following except

Accepted Answer

A)  β-oxidation. 
B)  acetyl-CoA. 
C)  glycerol. 
D)  lipase. 
E)  transamination. 
A)  β-oxidation. 
B)  acetyl-CoA. 
C)  glycerol. 
D)  lipase. 
E)  transamination.

Question 19

The change in free energy of a reaction varies.

Accepted Answer

A) True 
 B)False

Question 20

Please identify the True statement.

Accepted Answer

A)  Exergonic reactions consume energy because the starting compounds have less free energy than the products. 
B)  "Substrate" refers to a substance on which an enzyme acts to form products OR a surface on which an organism can grow. 
C)  A terminal electron acceptor is a chemical that is ultimately oxidized as a consequence of fermentation or respiration. 
D)  Aerobic respiration is a metabolic process in which electrons are transferred from the electron transport chain to an organic intermediate. 
E)  Activation energy is the energy required to create a bond in a chemical reaction. 
A)  Exergonic reactions consume energy because the starting compounds have less free energy than the products. 
B)  "Substrate" refers to a substance on which an enzyme acts to form products OR a surface on which an organism can grow. 
C)  A terminal electron acceptor is a chemical that is ultimately oxidized as a consequence of fermentation or respiration. 
D)  Aerobic respiration is a metabolic process in which electrons are transferred from the electron transport chain to an organic intermediate. 
E)  Activation energy is the energy required to create a bond in a chemical reaction.

Exam 6: Microbial Metabolism: Fueling Cell Growth

An atom that has a lower affinity for electrons than another is ________ than the other.

Coenzymes are derivatives of

Which of the following is NOT common to aerobic respiration, anaerobic respiration, AND fermentation?

Why would a cell ferment rather than respire?

Which is True of competitive inhibition?

NAD in its reduced form is symbolized as

Which of the following produces the most precursor metabolites?

Allosteric enzymes

How would cellulose-degrading bacteria in the rumen (stomachs) of a cow benefit the animal?

The small, non-protein molecules that can be readily separated from an enzyme and are responsible for transfer of atoms from one molecule to another are referred to as

Why was it necessary for the lab to inoculate a sample of the incubated tetrathionate broth onto a medium selective for Salmonella?

Enzymes are changed by the reaction as they raise the activation energy.

Cells degrade sugar largely to

Both glycolysis and the pentose phosphate pathway oxidize glucose to pyruvate.

Mercury in mercurochrome inhibits growth

Tetrathionate is an oxidized form of sulfur that can act as a terminal electron acceptor. What does the fact that S. enterica can grow in this medium this tell you about this organism?

Degradation of fats as an energy source involves all of the following except

The change in free energy of a reaction varies.

Please identify the True statement.

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

The Blueprint of Life, from DNA to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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