Question 1

During the citric acid cycle, an acetyl CoA molecule produced in the intermediate stage combines with a molecule of

Accepted Answer

A)   oxaloacetic acid.
B)   pyruvate.
C)   citrate.
D)   succinate.E) A) and B)
F) A) and C)

Question 2

Compare and contrast chemical energy and radiant energy. Into which broad category of energy (kinetic or potential) does each fit? What are two examples of each type of energy that relate to human physiology?

Accepted Answer

Chemical energy is potential energy and ...

Question 3

The optimal pH range for most human enzymes is

Accepted Answer

A)   1-2.
B)   4-6.
C)   6-8.
D)   8-10.
E)   13-14.F) A) and C)
G) A) and E)

Question 4

The reaction in which water and carbon dioxide combine to form carbonic acid is

Accepted Answer

A)   irreversible, as carbonic acid rapidly causes a drop in pH.
B)   reversible, and can proceed in either direction depending on the concentrations of the molecules.
C)   exergonic, and is an important energy source within the body.
D)   an exchange reaction in which protons are transferred between atoms.
E)   a catabolic reaction in which the formation of a larger molecule can lead to an increase in cell size.F) A) and D)
G) A) and B)

Question 5

The optimal pH range for the stomach enzyme pepsin is

Accepted Answer

A)   2-4.
B)   6-8.
C)   7.3-7.4.
D)   10-12.
E)   12.0-13.5.F) B) and E)
G) B) and D)

Question 6

In substrate-level phosphorylation, energy is first released to coenzymes and then transferred to form ATP.

Accepted Answer

A) True 
 B)False

Question 7

An enzyme that is described as a protein kinase is a(n)

Accepted Answer

A)   hydrolase that removes an amino acid from a protein.
B)   transferase that transfers a phosphate group to a protein substrate.
C)   ligase that adds an amino acid to a protein.
D)   isomerase that changes one protein into another.
E)   protease that transfers electrons from one protein to another.F) A) and E)
G) None of the above

Question 8

When multiple enzymes are organized in a metabolic pathway, each enzyme catalyzes one reaction and then releases the product.

Accepted Answer

A) True 
 B)False

Question 9

Extremely high temperatures break intramolecular interactions and ________ an enzyme, resulting in a loss of its function.

Accepted Answer

The answer of Extremely high temperatures break intramolecular interactions and...

Question 10

The proteins in the electron transport chain transport H+

Accepted Answer

A)   from the cytosol to the matrix.
B)   from the matrix to the outer compartment.
C)   from the outer compartment to the cytosol.
D)   from the outer compartment to the matrix.
E)   from the cristae to the matrix.F) C) and D)
G) None of the above

Question 11

Hexokinase is an enzyme involved in cellular respiration and its substrate is glucose. Considering this information, hexokinase must be located

Accepted Answer

A)   in the lumen of the stomach.
B)   in the lumen of the small intestine.
C)   inside the mitochondria of cells.
D)   in the cytosol of cells.E) B) and D)
F) B) and C)

Question 12

Explain the relationship between activation energy and reaction rate. For example, how would an increase in activation energy affect reaction rate? How do biological systems differ from lab settings when considering these chemical variables?

Accepted Answer

Higher activation energy requirements wo...

Question 13

The binding of ATP to phosphofructokinase inhibits the glycolytic pathway.

Accepted Answer

A) True 
 B)False

Question 14

In the first step of the electron transport chain, the coenzymes NADH and FADH2 are oxidized.

Accepted Answer

A) True 
 B)False

Question 15

The enzyme that harnesses the energy of H+ diffusion down its concentration gradient within a mitochondrion to make high-energy molecules for the cell is

Accepted Answer

A)   ATP phosphatase.
B)   ATP synthase.
C)   pyruvate decarboxylase.
D)   succinic dehydrogenase.
E)   creatine phosphatase.F) B) and C)
G) A) and D)

Question 16

Enzyme saturation occurs when substrate levels are so high that all enzyme molecules are actively engaged in the chemical reaction, and so further increases in substrate concentration do not increase reaction rate.

Accepted Answer

A) True 
 B)False

Question 17

All amino acids enter the cellular respiration pathway at the citric acid cycle.

Accepted Answer

A) True 
 B)False

Question 18

Briefly describe how enzymes are named. What is generally used for the root of the name, and what is generally used as the suffix? Provide one example.

Accepted Answer

The root is usually the substr...

Question 19

The first stage of cellular respiration is

Accepted Answer

A)   electron transport, and it occurs in the cytosol.
B)   electron transport, and it occurs in the mitochondria.
C)   glycolysis, and it occurs in the cytosol.
D)   glycolysis, and it occurs in the mitochondria.
E)   the citric acid cycle, and it occurs at the mitochondria.F) A) and B)
G) A) and C)

Question 20

Cofactors are generally proteins.

Accepted Answer

A) True 
 B)False

Exam 3: Energy, Chemical Reactions, and Cellular Respiration

Extremely high temperatures break intramolecular interactions and ________ an enzyme, resulting in a loss of its function.

Correct AnswerverifiedShow Answer

All amino acids enter the cellular respiration pathway at the citric acid cycle.

Correct AnswerverifiedShow Answer

Compare and contrast chemical energy and radiant energy. Into which broad category of energy (kinetic or potential) does each fit? What are two examples of each type of energy that relate to human physiology?

Correct AnswerverifiedChemical energy is potential energy and ...View AnswerShow Answer

The optimal pH range for most human enzymes is

Correct AnswerverifiedShow Answer

The binding of ATP to phosphofructokinase inhibits the glycolytic pathway.

Correct AnswerverifiedShow Answer

Explain the relationship between activation energy and reaction rate. For example, how would an increase in activation energy affect reaction rate? How do biological systems differ from lab settings when considering these chemical variables?

Correct AnswerverifiedHigher activation energy requirements wo...View AnswerShow Answer

The proteins in the electron transport chain transport H+

Correct AnswerverifiedShow Answer

During the citric acid cycle, an acetyl CoA molecule produced in the intermediate stage combines with a molecule of

Correct AnswerverifiedShow Answer

The first stage of cellular respiration is

Correct AnswerverifiedShow Answer

In the first step of the electron transport chain, the coenzymes NADH and FADH2 are oxidized.

Correct AnswerverifiedShow Answer

When multiple enzymes are organized in a metabolic pathway, each enzyme catalyzes one reaction and then releases the product.

Correct AnswerverifiedShow Answer

Enzyme saturation occurs when substrate levels are so high that all enzyme molecules are actively engaged in the chemical reaction, and so further increases in substrate concentration do not increase reaction rate.

Correct AnswerverifiedShow Answer

Hexokinase is an enzyme involved in cellular respiration and its substrate is glucose. Considering this information, hexokinase must be located

Correct AnswerverifiedShow Answer

The optimal pH range for the stomach enzyme pepsin is

Correct AnswerverifiedShow Answer

The reaction in which water and carbon dioxide combine to form carbonic acid is

Correct AnswerverifiedShow Answer

An enzyme that is described as a protein kinase is a(n)

Correct AnswerverifiedShow Answer

Cofactors are generally proteins.

Correct AnswerverifiedShow Answer

In substrate-level phosphorylation, energy is first released to coenzymes and then transferred to form ATP.

Correct AnswerverifiedShow Answer

The enzyme that harnesses the energy of H+ diffusion down its concentration gradient within a mitochondrion to make high-energy molecules for the cell is

Correct AnswerverifiedShow Answer

Briefly describe how enzymes are named. What is generally used for the root of the name, and what is generally used as the suffix? Provide one example.

Correct AnswerverifiedThe root is usually the substr...View AnswerShow Answer

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Chemical energy is potential energy and ...
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Higher activation energy requirements wo...
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The proteins in the electron transport chain transport H⁺

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In the first step of the electron transport chain, the coenzymes NADH and FADH₂ are oxidized.

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verified

Correct Answer
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Correct Answer
verified

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The enzyme that harnesses the energy of H⁺ diffusion down its concentration gradient within a mitochondrion to make high-energy molecules for the cell is

Correct Answer
verified

Correct Answer
verified
The root is usually the substr...
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