Question 1

Oxidation of nutrients by cells results in

Accepted Answer

A)   a requirement for energy which can be used to recharge ADP to ATP.
B)   a release of energy, which is released by converting ATP to ADP.
C)   a release of energy, which can be used to recharge ADP to ATP.
D)   a requirement of energy which can be obtained by converting ATP to ADP.
E)   either a release or a requirement for energy depending on what type of nutrient is available.F) A) and B)
G) None of the above

Question 2

Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities?

Accepted Answer

A)   E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.
B)   E. coli will be unable to build the peptidoglycan it needs for its cell wall.
C)   All amino acids are "essential" to E. coli.
D)   E. coli will be unable to perform amination.
E)   E. coli will use salvage pathways to make nucleotides.F) A) and C)
G) B) and D)

Question 3

Anabolic reactions

Accepted Answer

A)   are endergonic.
B)   involve dehydration synthesis.
C)   are endergonic and involve breaking down larger molecules into smaller molecules.
D)   are endergonic and involve dehydration synthesis.
E)   involve breaking down larger molecules into smaller molecules.F) None of the above
G) A) and E)

Question 4

The intermediate(s)  needed to synthesize lipids from sugar catabolism is (are)

Accepted Answer

A)   acetyl CoA.
B)   citric acid and dihydroxyacetone phosphate (DHAP) .
C)   citric acid.
D)   dihydroxyacetone phosphate (DHAP) .
E)   acetyl CoA and dihydroxyacetone phosphate (DHAP) .F) D) and E)
G) B) and D)

Question 5

Refer to the numbered steps in the figure when answering the question. Which step is a redox reaction?

Accepted Answer

A)   step 1
B)   step 3
C)   step 4
D)   step 6
E)   step 9F) C) and D)
G) A) and C)

Question 6

The main goal of fermentation is to sustain ATP production by glycolysis. This is accomplished by

Accepted Answer

A)   passing the electrons on NADH to pyruvic acid, regenerating NAD+ so glycolysis can continue.
B)   enables the cell to use its respiratory chain without oxygen being available.
C)   producing acids and alcohols which the microorganism can use as an alternative nutrient source when glucose is not available.
D)   producing acids which lower cellular pH to promote more efficient ATP recharge.
E)   diverting glycolysis intermediates into the pentose phosphate pathway.F) A) and E)
G) All of the above

Question 7

Which of the following factors may influence an enzyme's activity by altering its three- dimensional structure?

Accepted Answer

A)   temperature
B)   pH
C)   pH and temperature only
D)   competitive inhibitor
E)   pH, temperature, and competitive inhibitorF) B) and C)
G) A) and E)

Question 8

Ribozymes are enzymes which are made of protein but only work on RNA molecules as substrates.

Accepted Answer

A) True 
 B)False

Question 9

Biochemical tests are useful to microbiology because

Accepted Answer

A)   they can be used to identify microbes.
B)   they can be used to identify microbes and to identify potential pathogens in clinical samples.
C)   they can be used to detect metabolic end- products, intermediates, or particular enzymes.
D)   they can be used to identify potential pathogens in clinical samples.
E)   they can be used to identify microbes and to identify potential pathogens in clinical samples and they can be used to detect metabolic end- products, intermediates, or particular enzymes.F) A) and B)
G) None of the above

Question 10

Generally, purines and pyrimidines are not synthesized de novo but rather obtained through salvage pathways to recycle them from food because de novo synthesis has a high energy cost.

Accepted Answer

A) True 
 B)False

Question 11

The figure shows which process?

Accepted Answer

A)   allosteric inhibition
B)   competitive inhibition
C)   either allosteric inhibition, competitive inhibition, or non- competitive inhibition
D)   allosteric activation
E)   non- competitive inhibitionF) A) and E)
G) A) and B)

Question 12

In the typical ATP- ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored?

Accepted Answer

A)   the terminal two phosphate groups
B)   adenine
C)   the terminal phosphate group
D)   ribose
E)   all three phosphate groupsF) B) and C)
G) B) and E)

Question 13

Describe two factors which may increase enzyme activity and two factors which may decrease enzyme activity. Explain how each factor works to increase or decrease enzyme activity, and identify whether that factor is used internally by the cell (i.e. for regulation of a chemical reaction) or acts externally (i.e. is a component of the environment or a human- influenced component).

Accepted Answer

The following factors may influence enzy...

Question 14

Describe or diagram the relationship between catabolic pathways, anabolic pathways and the ATP- ADP cycle. Include in your answer an explanation of the role each of these plays in the metabolism of a cell.

Accepted Answer

All the chemical reactions that take pla...

Question 15

Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle?

Accepted Answer

A)   carbon dioxide
B)   ATP
C)   pyruvic acid
D)   NADH
E)   acetyl CoAF) None of the above
G) A) and D)

Question 16

Enzymes are necessary for cells because

Accepted Answer

A)   enzymes slow down chemical reactions that would otherwise occur too quickly to facilitate life.
B)   enzymes allow chemical reactions to occur under physiological conditions and within a time frame conducive to life.
C)   enzymes allow chemical reactions to occur under physiological conditions.
D)   enzymes allow chemical reactions to take place that would otherwise be impossible.
E)   enzymes allow chemical reactions to occur quickly enough to facilitate life.F) A) and B)
G) C) and E)

Question 17

Radioactive isotopes of various elements can be used to label molecules for use in studies of metabolic pathways. For example, 14C is a radioactive isotope of carbon and naturally occurs at much lower rates than non- radioactive 12C (i.e. most molecules contain 12C carbon atoms). A cell can be fed a nutrient molecule labeled with the radioactive isotope and scientists can detect where the radioactive isotope ends up. For each of the following scenarios, trace the radioactive isotope to where it ultimately would end up after moving through the cellular respiration, fermentation, or biosynthetic pathways. Only consider these metabolic pathways; do not consider any other cellular processes.
A. E. coli is fed 14C- labeled glucose and grown under aerobic conditions.
B. E. coli is fed 14C- labeled glucose and grown under anaerobic conditions (fermentation).
C. E. coli is fed 14C- labeled fatty acids and grown under aerobic conditions.
D. E. coli is fed 14C- labeled acetyl CoA and grown under conditions that promote biosynthetic pathways.

Accepted Answer

In scenario A, the 14C glucose would ent...

Question 18

Catabolic reactions

Accepted Answer

A)   are endergonic.
B)   are hydrolytic and involve breaking down larger molecules into smaller molecules.
C)   are hydrolytic.
D)   involve breaking down larger molecules into smaller molecules.
E)   are endergonic and are hydrolytic.F) B) and E)
G) C) and D)

Question 19

Cells harvest energy from nutrients by stripping electrons from them. In other words, the nutrients are oxidized.

Accepted Answer

A) True 
 B)False

Question 20

By the end of the Krebs cycle, every carbon originally in glucose is converted into carbon dioxide.

Accepted Answer

A) True 
 B)False

Exam 8: Microbial Metabolism

Enzymes are necessary for cells because

Correct Answer
verified

The figure shows which process?

Correct Answer
verified

Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities?

Correct Answer
verified

Oxidation of nutrients by cells results in

Correct Answer
verified

Catabolic reactions

Correct Answer
verified

Describe or diagram the relationship between catabolic pathways, anabolic pathways and the ATP- ADP cycle. Include in your answer an explanation of the role each of these plays in the metabolism of a cell.

Correct Answer
verified
All the chemical reactions that take pla...
View Answer

Correct Answer
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The following factors may influence enzy...
View Answer

By the end of the Krebs cycle, every carbon originally in glucose is converted into carbon dioxide.

Correct Answer
verified

The main goal of fermentation is to sustain ATP production by glycolysis. This is accomplished by

Correct Answer
verified

Refer to the numbered steps in the figure when answering the question. Which step is a redox reaction?

Correct Answer
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Anabolic reactions

Correct Answer
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Generally, purines and pyrimidines are not synthesized de novo but rather obtained through salvage pathways to recycle them from food because de novo synthesis has a high energy cost.

Correct Answer
verified

Ribozymes are enzymes which are made of protein but only work on RNA molecules as substrates.

Correct Answer
verified

Biochemical tests are useful to microbiology because

Correct Answer
verified

Correct Answer
verified
In scenario A, the 14C glucose would ent...
View Answer

Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle?

Correct Answer
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In the typical ATP- ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored?

Correct Answer
verified

The intermediate(s) needed to synthesize lipids from sugar catabolism is (are)

Correct Answer
verified

Which of the following factors may influence an enzyme's activity by altering its three- dimensional structure?

Correct Answer
verified

Cells harvest energy from nutrients by stripping electrons from them. In other words, the nutrients are oxidized.

Correct Answer
verified

Exam 8: Microbial Metabolism

Enzymes are necessary for cells because

Correct AnswerverifiedShow Answer

The figure shows which process?

Correct AnswerverifiedShow Answer

Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities?

Correct AnswerverifiedShow Answer

Oxidation of nutrients by cells results in

Correct AnswerverifiedShow Answer

Catabolic reactions

Correct AnswerverifiedShow Answer

Describe or diagram the relationship between catabolic pathways, anabolic pathways and the ATP- ADP cycle. Include in your answer an explanation of the role each of these plays in the metabolism of a cell.

Correct AnswerverifiedAll the chemical reactions that take pla...View AnswerShow Answer

Correct AnswerverifiedThe following factors may influence enzy...View AnswerShow Answer

By the end of the Krebs cycle, every carbon originally in glucose is converted into carbon dioxide.

Correct AnswerverifiedShow Answer

The main goal of fermentation is to sustain ATP production by glycolysis. This is accomplished by

Correct AnswerverifiedShow Answer

Refer to the numbered steps in the figure when answering the question. Which step is a redox reaction?

Correct AnswerverifiedShow Answer

Anabolic reactions

Correct AnswerverifiedShow Answer

Generally, purines and pyrimidines are not synthesized de novo but rather obtained through salvage pathways to recycle them from food because de novo synthesis has a high energy cost.

Correct AnswerverifiedShow Answer

Ribozymes are enzymes which are made of protein but only work on RNA molecules as substrates.

Correct AnswerverifiedShow Answer

Biochemical tests are useful to microbiology because

Correct AnswerverifiedShow Answer

Correct AnswerverifiedIn scenario A, the 14C glucose would ent...View AnswerShow Answer

Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle?

Correct AnswerverifiedShow Answer

In the typical ATP- ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored?

Correct AnswerverifiedShow Answer

The intermediate(s) needed to synthesize lipids from sugar catabolism is (are)

Correct AnswerverifiedShow Answer

Which of the following factors may influence an enzyme's activity by altering its three- dimensional structure?

Correct AnswerverifiedShow Answer

Cells harvest energy from nutrients by stripping electrons from them. In other words, the nutrients are oxidized.

Correct AnswerverifiedShow Answer

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All the chemical reactions that take pla...
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The following factors may influence enzy...
View Answer

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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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In scenario A, the 14C glucose would ent...
View Answer

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Correct Answer
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Correct Answer
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Correct Answer
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