Question 1

Exhibit 15A Consider the reaction of alcohol dehydrogenase.
  
-Refer to Exhibit 15A. Which molecule loses electrons?

Accepted Answer

A)  Ethanol 
B)  NAD+ 
C)  Acetaldehyde 
D)  NADH 
E)  H+ 
A)  Ethanol 
B)  NAD+ 
C)  Acetaldehyde 
D)  NADH 
E)  H+

Question 2

An isolated system can exchange ______ with its surroundings

Accepted Answer

A)  energy but not matter 
B)  matter but not energy 
C)  both matter and energy 
D)  neither matter nor energy 
A)  energy but not matter 
B)  matter but not energy 
C)  both matter and energy 
D)  neither matter nor energy

Question 3

Which of the following are examples of endergonic processes?

Accepted Answer

A)  protein synthesis and active transport 
B)  protein synthesis and oxidation of carbohydrates 
C)  active transport and oxidation of carbohydrates 
D)  oxidation of fats and of carbohydrates 
A)  protein synthesis and active transport 
B)  protein synthesis and oxidation of carbohydrates 
C)  active transport and oxidation of carbohydrates 
D)  oxidation of fats and of carbohydrates

Question 4

ATP is a good source of energy to run metabolic reactions for all the following reasons, except:

Accepted Answer

A)  The pyrophosphate bond has a high energy of hydrolysis. 
B)  The sugar group is very reactive. 
C)  The bonds between the phosphates are acid anhydrides. 
D)  The phosphate groups can combine readily with other molecules. 
E)  All of these explain why ATP is a good energy source. 
A)  The pyrophosphate bond has a high energy of hydrolysis. 
B)  The sugar group is very reactive. 
C)  The bonds between the phosphates are acid anhydrides. 
D)  The phosphate groups can combine readily with other molecules. 
E)  All of these explain why ATP is a good energy source.

Question 5

Which of the following is not a part of FAD?

Accepted Answer

A)  Ribitol 
B)  isoalloxazine 
C)  adenine 
D)  ribose 
E)  nicotinamide 
A)  Ribitol 
B)  isoalloxazine 
C)  adenine 
D)  ribose 
E)  nicotinamide

Question 6

In general, catabolism

Accepted Answer

A)  releases energy. 
B)  absorbs energy. 
C)  neither absorbs nor releases energy. 
A)  releases energy. 
B)  absorbs energy. 
C)  neither absorbs nor releases energy.

Question 7

The phosphorylation of ADP to produce ATP is endergonic because

Accepted Answer

A)  a negatively charged ion is bonded to a molecule that already carries a negative charge 
B)  ATP is more stable than ADP 
C)  the entropy of the products is less than that of the reactants 
D)  polyphosphate chains are the storage form of phosphorus in living organisms 
A)  a negatively charged ion is bonded to a molecule that already carries a negative charge 
B)  ATP is more stable than ADP 
C)  the entropy of the products is less than that of the reactants 
D)  polyphosphate chains are the storage form of phosphorus in living organisms

Question 8

What happens to the entropy when ATP is hydrolysed to ADP?

Accepted Answer

A)  Entropy increases 
B)  Entropy decreases. 
C)  Entropy doesn't change. 
D)  ATP has no entropy. 
A)  Entropy increases 
B)  Entropy decreases. 
C)  Entropy doesn't change. 
D)  ATP has no entropy.

Question 9

During reduction

Accepted Answer

A)  electrons are lost. 
B)  electrons are gained. 
C)  electrons may either be lost or gained. 
D)  hydrogen is formed. 
A)  electrons are lost. 
B)  electrons are gained. 
C)  electrons may either be lost or gained. 
D)  hydrogen is formed.

Question 10

"Oxidation" refers to

Accepted Answer

A)  the loss of oxygen. 
B)  the gain of oxygen. 
C)  the loss of electrons. 
D)  the gain of electrons. 
A)  the loss of oxygen. 
B)  the gain of oxygen. 
C)  the loss of electrons. 
D)  the gain of electrons.

Question 11

Living things are _____

Accepted Answer

A)  a closed system 
B)  an open system 
C)  an isolated system 
D)  none of these 
A)  a closed system 
B)  an open system 
C)  an isolated system 
D)  none of these

Question 12

Which of the following statements apply to anabolism?

Accepted Answer

A)  proceeds in stages 
B)  requires energy 
C)  requires reducing agents 
D)  all of these 
A)  proceeds in stages 
B)  requires energy 
C)  requires reducing agents 
D)  all of these

Question 13

Which of the following coenzymes is not a carrier of electrons in biological redox reactions?

Accepted Answer

A)  Coenzyme A 
B)  Niacin. 
C)  Riboflavin. 
D)  Transition metal ions, such as those of iron or copper. 
E)  All of these can be intermediate electron carriers. 
A)  Coenzyme A 
B)  Niacin. 
C)  Riboflavin. 
D)  Transition metal ions, such as those of iron or copper. 
E)  All of these can be intermediate electron carriers.

Question 14

The energy released during metabolism of nutrients can be used to synthesize ATP from ADP and phosphate.

Accepted Answer

A) True 
 B)False

Question 15

An example of an activation step in metabolism is

Accepted Answer

A)  the hydrolysis of a triacylglycerol. 
B)  the cis-trans isomerization of retinal. 
C)  the formation of an acyl derivative of coenzyme A. 
D)  the formation of the peptide bond. 
A)  the hydrolysis of a triacylglycerol. 
B)  the cis-trans isomerization of retinal. 
C)  the formation of an acyl derivative of coenzyme A. 
D)  the formation of the peptide bond.

Question 16

Which of the following are examples of exergonic processes?

Accepted Answer

A)  protein synthesis and active transport 
B)  protein synthesis and oxidation of carbohydrates 
C)  active transport and oxidation of carbohydrates 
D)  oxidation of fats and of carbohydrates 
A)  protein synthesis and active transport 
B)  protein synthesis and oxidation of carbohydrates 
C)  active transport and oxidation of carbohydrates 
D)  oxidation of fats and of carbohydrates

Question 17

I am performing a reaction, A → B, with ΔG°' = −5000 kJ/mol. I start the reaction with 10 mM A and no B. After allowing the reaction to proceed for 24 hrs at room temperature and atmospheric pressure, I analyze a sample of the reaction mix to find I now have 8 mM A and 2 mM B. Which of the following conclusions should I make?

Accepted Answer

A)  The reaction has reached equilibrium. 
B)  I should come back again later; equilibrium has not yet been reached. 
C)  The formation of B from A is thermodynamically unfavorable, so I should find another starting material to make B. 
D)  I must've screwed up; there's no way I could get that result with that ΔG°' 
A)  The reaction has reached equilibrium. 
B)  I should come back again later; equilibrium has not yet been reached. 
C)  The formation of B from A is thermodynamically unfavorable, so I should find another starting material to make B. 
D)  I must've screwed up; there's no way I could get that result with that ΔG°'

Question 18

What happens to the entropy of a molecule as the number of resonance structures increases?

Accepted Answer

A)  Entropy also increases. 
B)  Entropy decreases. 
C)  Entropy has no relationship to the number of resonance structures. 
A)  Entropy also increases. 
B)  Entropy decreases. 
C)  Entropy has no relationship to the number of resonance structures.

Question 19

In metabolism the term "activation" refers to

Accepted Answer

A)  conversion of a component of a metabolic pathway into a reactive compound. 
B)  addition of a catalyst. 
C)  bypassing endergonic reactions in a pathway. 
D)  bypassing the unreactive components of a pathway. 
A)  conversion of a component of a metabolic pathway into a reactive compound. 
B)  addition of a catalyst. 
C)  bypassing endergonic reactions in a pathway. 
D)  bypassing the unreactive components of a pathway.

Question 20

In general, the anabolic pathways tend to involve oxidation reactions.

Accepted Answer

A) True 
 B)False

Exam 15: The Importance of Energy Changes and Electron Transfer in Metabolism

Exhibit 15A Consider the reaction of alcohol dehydrogenase. -Refer to Exhibit 15A. Which molecule loses electrons?

An isolated system can exchange ______ with its surroundings

Which of the following are examples of endergonic processes?

ATP is a good source of energy to run metabolic reactions for all the following reasons, except:

Which of the following is not a part of FAD?

In general, catabolism

The phosphorylation of ADP to produce ATP is endergonic because

What happens to the entropy when ATP is hydrolysed to ADP?

During reduction

"Oxidation" refers to

Living things are _____

Which of the following statements apply to anabolism?

Which of the following coenzymes is not a carrier of electrons in biological redox reactions?

The energy released during metabolism of nutrients can be used to synthesize ATP from ADP and phosphate.

An example of an activation step in metabolism is

Which of the following are examples of exergonic processes?

What happens to the entropy of a molecule as the number of resonance structures increases?

In metabolism the term "activation" refers to

In general, the anabolic pathways tend to involve oxidation reactions.

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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