Question 1

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. A

Question 2

The body allows energy consuming reactions to occur by coupling them with reactions which have a negative Δ G.

Accepted Answer

A) True 
 B)False  True

Question 3

"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. C

Question 4

Explain the differences between catabolism and anabolism.

Accepted Answer

Catabolism refers to the breakdown of nu

Question 5

The production of larger molecules from smaller ones is called

Accepted Answer

A)  metabolism. 
B)  catabolism. 
C)  anabolism. 
D)  none of these 
A)  metabolism. 
B)  catabolism. 
C)  anabolism. 
D)  none of these

Question 6

In order to initiate many metabolic pathways it is necessary to activate the starting materials.

Accepted Answer

A) True 
 B)False

Question 7

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 8

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 9

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

Accepted Answer

A) True 
 B)False

Question 10

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 11

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 12

An oxidizing agent

Accepted Answer

A)  loses oxygen. 
B)  gains oxygen. 
C)  loses electrons. 
D)  gains electrons. 
A)  loses oxygen. 
B)  gains oxygen. 
C)  loses electrons. 
D)  gains electrons.

Question 13

​ Among the following organophosphates, which compound has the highest amount of free energy of hydrolysis?

Accepted Answer

A)  Phosphoenolpyruvate 
B)  Glucose 6-phosphate 
C)  Adenosine triphosphate 
D)  Acetyl phosphate 
A)  Phosphoenolpyruvate 
B)  Glucose 6-phosphate 
C)  Adenosine triphosphate 
D)  Acetyl phosphate

Question 14

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 15

Which of the following is not a mechanism used to activate substrates for further metabolism?

Accepted Answer

A)  Addition of a phosphate group. 
B)  Combination with a vitamin, such as coenzyme A. 
C)  Hydrolyzing a polymer into its component monomers. 
D)  Addition of a phosphate group or combining with a vitamin. 
E)  All of these processes activate substrates. 
A)  Addition of a phosphate group. 
B)  Combination with a vitamin, such as coenzyme A. 
C)  Hydrolyzing a polymer into its component monomers. 
D)  Addition of a phosphate group or combining with a vitamin. 
E)  All of these processes activate substrates.

Question 16

Biochemists use a modified value for standard Δ G values because

Accepted Answer

A)  all reagents are not at a 1 molar concentration. 
B)  the pH in living systems is seldom, if ever, near 0. 
C)  the concentration of water is not at 1 molar concentration. 
D)  the reagents are not one molar and the pH = 7. 
E)  All of these justify why biochemists use a special Δ G value. 
A)  all reagents are not at a 1 molar concentration. 
B)  the pH in living systems is seldom, if ever, near 0. 
C)  the concentration of water is not at 1 molar concentration. 
D)  the reagents are not one molar and the pH = 7. 
E)  All of these justify why biochemists use a special Δ G value.

Question 17

When we say that the efficiency of glycolysis is about 33% we mean that

Accepted Answer

A)  2 ATP are produced and 6 ATP are involved in the overall process 
B)  2 ATP are produced in the oxidation of glucose, which contains six carbon atoms 
C)  the energy used to phosphorylate 2 ATP is 33% of the energy released in the process 
D)  all of these 
A)  2 ATP are produced and 6 ATP are involved in the overall process 
B)  2 ATP are produced in the oxidation of glucose, which contains six carbon atoms 
C)  the energy used to phosphorylate 2 ATP is 33% of the energy released in the process 
D)  all of these

Question 18

I am performing a reaction, A → B, with Δ G ° ' = − 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 Δ G ° ' 
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 Δ G ° '

Question 19

The efficiency of aerobic metabolism is greater than that of anaerobic metabolism even though much more energy is released in aerobic than in anaerobic metabolism because

Accepted Answer

A)  aerobic metabolism is linked to oxygen, which is a more powerful oxidizing agent than those in anaerobic metabolism 
B)  aerobic metabolism produces carbon dioxide and water 
C)  aerobic metabolism traps much more energy in the form of ATP than does anaerobic metabolism 
D)  anaerobic metabolism produces two- and three-carbon compounds 
A)  aerobic metabolism is linked to oxygen, which is a more powerful oxidizing agent than those in anaerobic metabolism 
B)  aerobic metabolism produces carbon dioxide and water 
C)  aerobic metabolism traps much more energy in the form of ATP than does anaerobic metabolism 
D)  anaerobic metabolism produces two- and three-carbon compounds

Question 20

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

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

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

The body allows energy consuming reactions to occur by coupling them with reactions which have a negative Δ G.

"Oxidation" refers to

Explain the differences between catabolism and anabolism.

The production of larger molecules from smaller ones is called

In order to initiate many metabolic pathways it is necessary to activate the starting materials.

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

In general, catabolism

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

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

An example of an activation step in metabolism is

An oxidizing agent

​ Among the following organophosphates, which compound has the highest amount of free energy of hydrolysis?

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

Which of the following is not a mechanism used to activate substrates for further metabolism?

Biochemists use a modified value for standard Δ G values because

When we say that the efficiency of glycolysis is about 33% we mean that

The efficiency of aerobic metabolism is greater than that of anaerobic metabolism even though much more energy is released in aerobic than in anaerobic metabolism because

Living things are _____

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 the 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

Filters

Among the following organophosphates, which compound has the highest amount of free energy of hydrolysis?