Archive for February 2017

Most CO2 from catabolism is released during

Naim 15:26

Most CO2 from catabolism is released during



A) glycolysis.
B) the citric acid cycle.
C) lactate fermentation.
D) electron transport.
E) oxidative phosphorylation.








Answer: B

Which of the following is a true distinction between fermentation and cellular respiration?

Naim 15:25

Which of the following is a true distinction between fermentation and cellular respiration?



A. Only respiration oxidized Glucose
B. NADH is oxidized by the electron transport chain in respiration only
C. Fermentation, but not respiration, is an example of a catabolic pathway
D. Substrate-level phosphorylation is unique to fermentation
E. NAD+ functions as an oxidizing agent only in respiration








Answer: B

Cells do not catalyze carbon dioxide because

Naim 15:25

Cells do not catalyze carbon dioxide because 




A. It's double bonds are too stable to be broken
B. CO2 has fewer binding electrons than other organic compounds
C. CO2 is already completely reduced
D. CO2 is already completely oxidized
E. The molecule has too few atoms







Answer: D

In mitochondria, exergonic redox reactions

Naim 15:24

In mitochondria, exergonic redox reactions




A. Are the source of energy driving prokaryotic ATP synthesis
B. Are directly coupled to substrate-level phosphorylation
C. Provide the energy that establishes the proton gradient
D. Reduce carbon atoms to carbon dioxide
E. Are coupled via phosphorylated intermediates to endergonic processes






Answer: C

The immediate energy source that drives ATP Synthesis by ATP synthase during oxidative phosphorylation is

Naim 15:24

The immediate energy source that drives ATP Synthesis by ATP synthase during oxidative phosphorylation is




A. The oxidation of glucose and other organic compounds
B. The flow of electrons down the electron transport chain
C. The affinity of oxygen for electrons
D. The H+ concentration gradient across the inner mitochondrial membrane
E. The transfer of phosphate to ADP





Answer: D

Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur?

Naim 15:24

Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur?



A. In the photosynthesis cells in the light, while photosynthesis occurs concurrently
B. In non-photosynthesizing cells only
C. In cells that are storing glucose only
D. In photosynthesizing cells in dark periods and in other tissues all the time
E. In photosynthesizing cells in the light and in other tissues in the dark







Answer: D

What is the purpose of beta oxidation in respiration?

Naim 15:23

What is the purpose of beta oxidation in respiration?




A. Oxidation of glucose
B. Oxidation of pyruvate
C. Feedback regulation
D. Control of ATP accumulation
E. Breakdown of fatty acids






Answer: E

Phosphofructokinase is an allosterically enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1, 6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to

Naim 15:23

Phosphofructokinase is an allosterically enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1, 6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to 


A. Inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle
B. Activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle
C. Inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle
D. Activate the enzyme and increase the rates of glycolysis and the citric acid cycle
E. Inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate







Answer: A

Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase?

Naim 15:23

Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase?




A. It is activated by AMP
B. It is activated by ATP
C. It is inhibited by citrate, an intermediate of the citric acid cycle
D. It catalyzes the conversion of fructose-6-phosphate, an early step of glycolysis
E. It is an allosterically enzyme






Answer: E

You have a friend who lost 7kg of fat on a low carb diet. How did the fat leave her body?

Naim 15:22

You have a friend who lost 7kg of fat on a low carb diet. How did the fat leave her body?




A. It was released as CO2 and H2O
B. Chemical energy was converted to hear and then released
C. It was converted to ATP, which weighs much less than fat
D. It was broken down to amino acids and eliminated from the body
E. It we converted to urine and eliminated from the body




Muscle cells, when an individual is exercising heavily and when the muscle becomes oxygen deprived, convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

Naim 15:21

Muscle cells, when an individual is exercising heavily and when the muscle becomes oxygen deprived, convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?




A. It is converted to NAD+
B. It produced CO2 and water
C. It is taken to the liver and converted back to pyruvate
D. It reduces FADH2 to FAD+
E. It is converted to alcohol





Answer: C

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Naim 15:21

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?




A. It produces much less ATP than does oxidative phosphorylation
B. It is found in the cytosol, does not involve oxygen, and is present in most organisms
C. It is found in prokaryotic cells but not in eukaryotic cells
D. It relies on chemiosmosis which is a metabolic mechanism present only in the first cells-prokaryotic cells
E. It's requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells






Answer: B

Glycolysis is thought to be one of the most ancient of metabolic processes. Which statement supports this idea?

Naim 15:20

Glycolysis is thought to be one of the most ancient of metabolic processes. Which statement supports this idea?



A. Glycolysis is the most widespread metabolic pathway
B. Glycolysis neither uses nor needs O2
C. Glycolysis is found in all eukaryotic cells
D. The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed organelle
E. Ancient prokaryotic cells, the most primitive of cells, made extensive use of glycolysis long before oxygen was present in earths atmosphere






Answer: A

An organism is discovered that consumes a considerable amount of sugar, yet it does not gain much weight when denied air. Curiously, the consumption of sugar increases as the air is removed from the organisms environment, but the organism seems to thrive even in the absence of air. When return a normal air, the organism does fine. Which of the following best describes an organism?

Naim 15:20

An organism is discovered that consumes a considerable amount of sugar, yet it does not gain much weight when denied air. Curiously, the consumption of sugar increases as the air is removed from the organisms environment, but the organism seems to thrive even in the absence of air. When return a normal air, the organism does fine. Which of the following best describes an organism?




A. It must use a molecule other than oxygen to accept electrons from the electron transport chain
B. It is a normal eukaryotic organism
C. The organism obviously lacks the citric acid cycle and electron transport chain
D. It is an anaerobic organism
E. It is a facultative anaerobic





Answer: E

Which of the following describes ubiquinone?

Naim 15:17

Which of the following describes ubiquinone?




A. A protein in the electron transport chain
B. A small hydrophobic coenzyme
C. A substrate for synthesis of FADH
D. A vitamin needed for efficient glycolysis
E. An essential amino acid





Answer: B

The accompanying figure shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain.

Naim 15:16

The accompanying figure shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain.



A. Oxygen, CO2, and water
B. NAD+, FAD, and electrons
C. NADH, FADH2, and protons
D. NADH, FADH2, and electrons
E. Oxygen and electrons






Answer: D

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost. It should be possible to reconstitute the abilities of the vesicles if which of the following is added?

Naim 15:16

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost.
It should be possible to reconstitute the abilities of the vesicles if which of the following is added?



A. Cytochrome
B. Extra NADH
C. a second membrane surface
D. More electrons
E. Intact ATP synthase








Answer: E

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost. After the second agitation of the membrane vesicles, what must be lost from the membrane?

Naim 15:15

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost.
After the second agitation of the membrane vesicles, what must be lost from the membrane?



A. The ability of NADH to transfer electrons to the first acceptor in the electron transport chain
B. The prosthetic groups like heme from the transport system
C. Cytochrome
D. ATP synthase, in whole or in part
E. The contact required between inner and outer membrane surfaces









Answer: D

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost. After the first disruption, when electron transfer and ATP synthesis occurs, what must be present?

Naim 15:15

Exposing inner mitochondrial membrane's to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal inside out. These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated still further however, the ability to synthesize ATP is lost.
After the first disruption, when electron transfer and ATP synthesis occurs, what must be present?




A. All of the electron transport proteins as well as ATP Synthase
B. All of the electron transport system and the ability to add CoA to acetyl groups
C. The ATP synthase system is sufficient
D. The electron transport system is sufficient
E. Plasma membrane like those bacteria use for respiration





Answer: A

In liver cells, the inter-mitochondrial membrane's are about five times the area of the outer mitochondrial membrane, about 17 times that of the cells plasma membrane. What purpose must this serve?

Naim 15:15

In liver cells, the inter-mitochondrial membrane's are about five times the area of the outer mitochondrial membrane, about 17 times that of the cells plasma membrane. What purpose must this serve?



A. It allows for increased rate of glycolysis
B. It allows for increased rate of citric acid cycle
C. It increased the surface for oxidative phosphorylation
D. It increases the surface for substrate-level phosphorylation
E. It allows the liver cell to have fewer mitochondria






Answer: C

What is proton-motive force?

Naim 15:14

What is proton-motive force?




A. The force required to remove an electron from hydrogen
B. The transmembrane proton concentration gradient
C. Movement of hydrogen into the intermembrane space
D. Movement of hydrogen into the mitochondrion
E. The addition of hydrogen to NAD+





Answer: B

Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy. The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency if cellular respiration for the mutant organism that produces only 29 moles of ATP for every mole of glucose oxidized, rather than the usual 36 to 38 mold of ATP?

Naim 15:14

Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy. The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency if cellular respiration for the mutant organism that produces only 29 moles of ATP for every mole of glucose oxidized, rather than the usual 36 to 38 mold of ATP?



A. 0.4%
B. 25%
C. 30%
D. 40%
E. 60%








Answer: C

It is possible to prepare vesicles from portions of the inner membrane of the mitochondrial components. Which one of the following processes could still be carried on by this isolated inner membrane?

Naim 12:07

It is possible to prepare vesicles from portions of the inner membrane of the mitochondrial components. Which one of the following processes could still be carried on by this isolated inner membrane?



A. The citric acid cycle
B. Oxidative phosphorylation
C. Glycolysis and fermentation
D. Reduction of NAD+
E. Both the citric acid cycle and oxidative phosphorylation







Answer: B

Where is ATP synthase in the mitochondrial?

Naim 12:06

Where is ATP synthase in the mitochondrial?




A. Cytosol
B. Electron transport chain
C. Outer membrane
D. Inner membrane
E. Mitochondrial matrix







Answer: D

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the

Naim 12:06

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the




A. Formation of ATP
B. REDUCTION OF NAD+
C. Restoration of the Na+/K+ balance across the membrane
D. Creation of protein gradient
E. Lowering of pH in the mitochondrial matrix





Answer: D

The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is

Naim 12:06

The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is




A. Oxidation of glucose to CO2 and water
B. The thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers
C. The final transfer of electrons to oxygen
D. The difference in H+ concentrations on opposite sides of the inner mitochondrial membrane
E. The thermodynamically favorable of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP






Answer: D

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP+P1 to ATP?

Naim 12:05

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP+P1 to ATP?



A. Energy released as electrons flow through the ETC
B. energy released from substrate-level phosphorylation
C. Energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix
D. Energy released from movement of protons through ATP synthase
E. No external source of energy is required because the reaction is exergonic









Answer: D

Inside an active mitochondrion, most electrons follow which pathway?

Naim 12:05

Inside an active mitochondrion, most electrons follow which pathway?



A. Glycolysis, NADH, oxidative phosphorylation, ATP, oxygen
B. Citric acid cycle, FADH2, ETC, ATP
C. ETC, CAC, ATP, oxygen
D. Pyruvate, CAC, ATP, NADH, oxygen
E. CAC, NADH, ETC, oxygen







Answer: E

The primary role of oxygen in cellular respiration is to

Naim 12:05

The primary role of oxygen in cellular respiration is to



A. Yield energy in the form of ATP as it is passed down the respiratory chain
B. Act as an acceptor for electrons and hydrogen, forming water
C. Combine with carbon, forming CO2
D. Combine with lactate, forming pyruvate
E. Catalyze the reactions of glycolysis







Answer: B

Which of the following describes the sequence of electron carriers in the ETC, starting with the least electronegative?

Naim 12:04

Which of the following describes the sequence of electron carriers in the ETC, starting with the least electronegative?




A. Ubiquinone(Q), cytochromes (Cyt), FMN, Fe•S
B. Cytochromes (Cyt), FMN, ubiquinone, Fe•S
C. Fe•S, FMN, cytochrome (Cyt), ubiquinone
D. FMN, Fe•S, ubiquinone, cytochrome(Cyt)
E. Cytochrome, Fe•S, ubiquinone, FMN






Answer: D

During aerobic respiration, electrons travel downhill in which sequence?

Naim 12:03

During aerobic respiration, electrons travel downhill in which sequence?




A. Food -> citric acid cycle-> ATP-> NAD+
B. Food-> NADH-> ETC-> Oxygen
C. Glucose-> pyruvate-> ATP-> oxygen
D. Glucose-> ATP-> ETC-> NADH
E. Food-> glycolysis-> citric acid cycle-> NADH-> ATP






Answer: B

Cellular respiration harvests the most chemical energy from which of the following?

Naim 12:02

Cellular respiration harvests the most chemical energy from which of the following?



A. Substrate-level phosphorylation
B. Chemiosmotic phosphorylation
C. Converting oxygen to ATP
D. Transferring electrons from organic molecules to pyruvate
E. Generating carbon dioxide and oxygen in the electron transport chain







Answer: B

A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal cod the following, which is the best explanation of his condition?

Naim 12:02

A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal cod the following, which is the best explanation of his condition?




A. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane
B. His cells cannot move NADH from glycolysis into the mitochondria
C. His cells contain something that inhibits oxygen used in his mitochondria
D. His cells lack the enzyme in glycolysis that forms pyruvate
E. His cells have a defective electron transport chain, so glucose goes to lactate instead of acetyl CoA.







Answer: A

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

Naim 12:01

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?



A. Glycolysis and the oxidation of pyruvate to acetyl CoA
B. Oxidation of pyruvate to acetyl CoA and the citric acid cycle
C. The citric acid cycle and oxidative phosphorylation
D. Oxidative phosphorylation and fermentation
E. Fermentation and glycolysis







Answer: B

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2. 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A. Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?

Naim 12:00

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2. 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A.
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?



A. Lactate
B. Glyceraldehyde-3-phosphate
C. Oxaloacetate
D. Acetyl CoA
E. Citrate







Answer: D

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2. 2) is oxidized to form a two-carbon compound called acetate and 3) is bonded to coenzyme A How does the pyruvate enter the mitochondrion?

Naim 12:00

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2. 2) is oxidized to form a two-carbon compound called acetate and 3) is bonded to coenzyme A
How does the pyruvate enter the mitochondrion?



A. Active transport
B. Diffusion
C. Facilitated diffusion
D. Through a channel
E. Through a pore








Answer: A

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A. Why is coenzyme A, a sulfur containing molecule derived from a B vitamin, added?

Naim 11:59

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A.
Why is coenzyme A, a sulfur containing molecule derived from a B vitamin, added?



A. Because sulfur is needed for the molecule to enter the mitochondrion
B. In order to utilize this portion of B vitamin which would otherwise be a waste product from another pathway
C. To provide a relatively unstable molecule whose acetyl portion can readily bond to oxaloacetate
D. Because it drives the reaction that regenerates NAD+







Answer: C

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1.) loses a carbon, which is given off as a molecule of CO2. 2.) is oxidized to form a two-carbon compound called acetate, and 3.) is bonded to coenzyme A. These three steps result in the formation of

Naim 11:59

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1.) loses a carbon, which is given off as a molecule of CO2. 2.) is oxidized to form a two-carbon compound called acetate, and 3.) is bonded to coenzyme A.
These three steps result in the formation of 




A. Acetyl CoA, O2, and ATP
B. Acetyl CoA, FADH2, and CO2
C. Acetyl CoA, FAD, H2, and CO2
D. Acetyl CoA, NADH, H+, and CO2
E. Acetyl CoA, NAD+, ATP, and CO2






Answer: D

Why is glycolysis described as having an investment phase and a payoff phase?

Naim 11:59

Why is glycolysis described as having an investment phase and a payoff phase?



A. It both splits molecules and assembles molecules
B. It attaches and detaches phosphate group
C. It used glucose and generates pyruvate
D. It shifts molecules from cytosol to mitochondrion
E. It uses stored ATP and then forms a net increase in ATP






Answer: E

What kind of metabolic poison would most directly interfere with glycolysis?

Naim 11:58

What kind of metabolic poison would most directly interfere with glycolysis?





A. An agent that reacts with oxygen and depleted its concentration in the cell
B. An agent that binds to pyruvate and inactivates it
C. An agent that closely mimics the structure of glucose but is not metabolized
D. An agent that reacts with NADH and oxidizes it to NAD+
E. An agent that blocks the passage of electrons along the electron transport chain







Answer: C

A molecule that is phosphorylated

Naim 11:58

A molecule that is phosphorylated 




A. Has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate
B. Has a decreased chemical reactivity; it is less likely to provide energy for cellular work
C. Has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate
D. Has an increased chemical reactivity: it is primed to do cellular work
E. Has less energy than before its phosphorylation and therefore less energy for cellular work






Answer: D

In glycolysis, for each molecule for glucose oxidized to pyruvate

Naim 11:58

In glycolysis, for each molecule for glucose oxidized to pyruvate 



A. 2 molecules of ATP are used and 2 molecules of ATP are produced
B. 2 molecules of ATP are used and 4 molecules of ATP are produced
C. 4 molecules of ATP are used and 2 molecules of ATP are produced
D. 2 molecules of ATP are used and 6 molecules of ATP are produced
E. 6 molecules of ATP are used and 6 molecules of ATP are produced






Answer: B

Starting with one molecule of glucose, the "net" products of glycolysis would be

Naim 11:58

Starting with one molecule of glucose, the "net" products of glycolysis would be



A. 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O
B. 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O
C. 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O
D. 6CO2, 6H2O, 2 ATP, and 2 pyruvate
E. 6 CO2, 6H2O, 36 ATP, and 2 citrate








Answer: B

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mole and the free energy for the reduction of NAD+ to NADH is +53 kcal/mole. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Naim 11:57

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mole and the free energy for the reduction of NAD+ to NADH is +53 kcal/mole. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?



A. Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis.
B. Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat
C. Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis
D. There is no CO2 or water produced as products of glycolysis
E. Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule.







Answer: C

Why are carbohydrates and fats considered high energy foods?

Naim 11:56

Why are carbohydrates and fats considered high energy foods?




A. They have a lot of oxygen atoms
B. They have no nitrogen in their makeup
C. They have very long carbon skeletons
D. They have a lot of electrons associated with hydrogen
E. They are easily reduced







Answer: D

An electron loses potential energy when it

Naim 11:56

An electron loses potential energy when it 




A. Shifts to a less electronegative atom
B. Shifts to a more electronegative atom
C. Increases its kinetic energy
D. Increases its activity as an oxidizing agent
E. Attaches itself to NAH+






Answer: B

The ATP made during glycolysis is generated by

Naim 11:55

The ATP made during glycolysis is generated by



A. Substrate-level phosphorylation
B. Electron transport
C. Photo phosphorylation
D. Chemiosmosis
E. Oxidation of NAD+ and NADH






Answer: A

Where does glycolysis take place?

Naim 11:55

Where does glycolysis take place?




A. Mitochondrial matrix
B. Mitochondrial outer membrane
C. Mitochondrial inner membrane
D. Mitochondrial intermembrane space
E. Cytosol





Answer: E

Which of the following statements describes NAD+?

Naim 11:51

Which of the following statements describes NAD+? 



A. NAD+ is reduced to NADH during both glycolysis and the citric acid cycle
B. NAD+ has more chemical energy than NADH
C. NAD+ is reduced by the action of hydrogenases
D. NAD+ can donate electrons for use in oxidative phosphorylation
E. In the absence of NAD+, glycolysis can still function







Answer: A

Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?

Naim 11:49

Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?





A. The covalent bond in organic molecules are higher energy bonds than those in water and carbon dioxide
B. Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as C)
C. The oxidation of organic compounds can be used to make ATP
D. the electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds
E. The covalent bonds in O2 is unstable and easily broken by electron from organic molecules






Answer: B

Which of the following the most correct interpretation of the figure?

Naim 23:22

Which of the following the most correct interpretation of the figure?


a.) ADP + Pi are a set of molecule that store energy for catabolism
b.) Pi acts as a shuttle molecule to move energy from ATP to ADP
c.) energy from catabolism can be used directly for performing cellular work
d.) ATP is a molecule that acts as an intermediary to store energy for cellular work








Answer: D

According to the induced fit hypothesis of enzyme catalysis,_________

Naim 23:22

According to the induced fit hypothesis of enzyme catalysis,_________



a.) the binding of the substrate changes the shape of the enzyme's active site
b.) the binding of the substrate depends on the shape of the active site
c.) some enzymes change their structure when activators bind to the enzyme
d.) the active site created microenvironment ideal for the reaction





Answer: A

For living organisms, which of the following is an important consequence of the first law of thermodynamics?

Naim 23:22

For living organisms, which of the following is an important consequence of the first law of thermodynamics?




a.) The organism ultimately must obtain all of the necessary energy for life from its environment
b.) the entropy of an organism decreases with time as the organism grows in complexity
c.) organism grow by converting energy into organic matter
d.) the energy content of an organism is constant








Answer: A

Which of the following is an example of cooperatively?

Naim 23:21

Which of the following is an example of cooperatively?




a.) binding of an ATP molecule along with one of the substrate molecules in an active site
b.) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway
c.) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway
d.) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three







Answer: D

Biological evolution of life on Earth, from simple prokaryote-like cells to large, multicellular eukaryotic organisms,______.

Naim 23:21

Biological evolution of life on Earth, from simple prokaryote-like cells to large, multicellular eukaryotic organisms,______.




a.) has occurred in accordance with the laws of thermodynamics, by expending Earth's energy resources and causing an increase in the entropy of the planet
b.) has caused an increase in the entropy of the planet
c.) has occurred in accordance with the laws of thermodynamics
d.) has been made possible by expending Earth's energy resources





Answer: C

A system at chemical equilibrium_____.

Naim 23:21

A system at chemical equilibrium_____.




a.) can do no work
b.) releases energy at a steady rate
c.) has zero kinetic energy
d.) consumes energy at a steady rate



Answer: A

The mathematical expression for the change in free energy of a system is delta G= DeltaH-TdeltaS. Which of the following is (are) correct?

Naim 23:20

The mathematical expression for the change in free energy of a system is delta G= DeltaH-TdeltaS. Which of the following is (are) correct?




a.) delta G is the change in free energy
b.) T is the temperature in degree Celsius
c.) delta S is the change in enthalpy, a measure of randomness
d.) delta H is the change in entropy, the energy available to do work






Answer: A

Which of the following is true of enzymes?

Naim 23:18

Which of the following is true of enzymes?



a.) enzyme function is increased if the 3-d structure or conformation of an enzyme is altered
b.) enzymes increase the rate of chemical reaction by lowering activation energy barriers
c.) enzymes increase the rate of chemical reaction by providing activation energy to the substrate
d.) enzyme function is independent of physical and chemical environmental factors such as pH and temperature






Answer: B

In a biological reaction, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by masonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of masonic acid reduces the inhibitory effect of masonic acid. Select the correct identification of the molecules described in the reaction.

Naim 23:18

In a biological reaction, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by masonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of masonic acid reduces the inhibitory effect of masonic acid. Select the correct identification of the molecules described in the reaction.






a.) succinate is the substrate, and fumarate is the product in the reaction
b.) fumarate is the product, and masonic acid is a noncompetitive inhibitor in the reaction
c.) succinate dehydrogenase is the enzyme, and fumarate is the substrate in the reaction
d.) succinate dehydrogenase is the enzyme, and masonic acid is the substrate in the reaction







Answer: A

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Naim 23:17

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?



a.) life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe
b.) as consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth
c.) living organisms are able to transform energy into entropy
d.) living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time







Answer: B

What is substance X?

Naim 23:17

What is substance X?



a.) a substrate
b.) an intermediate
c.) an allosteric inhibitor
d.) the product







Answer: A

Which of the following is a statement of the first law of thermodynamics?

Naim 23:16

Which of the following is a statement of the first law of thermodynamics?



a.) energy cannot be transferred or transformed
b.) the entropy of the universe is decreasing
c.) the entropy of the universe is constant
d.) energy cannot be created or destroyed







Answer: D

The active site of an enzyme is the region that______

Naim 23:16

The active site of an enzyme is the region that______




a.) binds the allosteric regulators of the enzyme
b.) binds the noncompetitive inhibitors of the enzyme
c.) is inhibited by the presence of a coenzyme or a cofactor
d.) is involved in the catalytic reaction of the enzyme







Answer: D

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a delta G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the delta G for the new reaction?

Naim 23:15

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a delta G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the delta G for the new reaction?



a.) 0 kcal/mol
b.) +20 kcal/mol
c.) -20 kcal/mol
d.) -40 kcal/mol







Answer: C

Anabolic pathways_____.

Naim 23:15

Anabolic pathways_____.




a.) consume energy to build up polymers from monomers
b.) consume energy to decrease the entropy of the organism and its environment
c.) are usually highly spontaneous chemical reactions
d.) release energy as they degrade polymers to monomers






Answer: A

Chemical equilibrium is relatively rare in living cells. An example of a reaction at chemical equilibrium in a cell would be_____.

Naim 23:14

Chemical equilibrium is relatively rare in living cells. An example of a reaction at chemical equilibrium in a cell would be_____.




a.) an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplies only by heat from the environment
b.) a chemical reaction in which both the reactants and products are not being produced or used in any active metabolic pathway at that time in the cell
c.) one in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium
d.) one in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings







Answer: B

Why is ATP an important molecule in metabolism?

Naim 23:14

Why is ATP an important molecule in metabolism?





a.) its hydrolysis provides an input of free energy for exergonic reactions
b.) its terminal phosphate bond has higher energy than the other two phosphate bonds
c.) its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy
d.) it provides energy coupling between exergonic and endergonic reactions






Answer: D

Which of the following statements is representative of the second law of thermodynamics?

Naim 23:14

Which of the following statements is representative of the second law of thermodynamics?





a.) without an input of energy, organisms would tend toward decreasing entropy
b.) conversion of energy from one for to another is always accompanied by some gain of free energy
c.) every energy transformation by a cell decreases the entropy of the universe
d.) cells require a constant input of energy to maintain their high level of organization









Answer: D

Which of the following is true for all exergonic reactions?

Naim 23:13

Which of the following is true for all exergonic reactions?




a.) the reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants
b.) the products have more total energy than the reactants
c.) the reaction proceeds with a net release of free energy
d.) a net input of energy from the surrounding is required for the reactions to proceed






Answer: C

Which of the following is true of metabolism in its entirety in all organisms?

Naim 23:12

Which of the following is true of metabolism in its entirety in all organisms?



a.) metabolism consists of all the energy transformation reactions in an organism
b.) metabolism manages the increase of entropy in an organism
c.) metabolism uses all of an organism's resources
d.) metabolism depends on a constant supply of energy from food





Answer: A


Atoms whose outer electron shells contain eight electrons tend to

Naim 02:21

Atoms whose outer electron shells contain eight electrons tend to





  1. be isotopes and very radioactive.
  2. form covalent bonds in aqueous solutions.
  3. be stable and chemically nonreactive, or inert.
  4. be unstable and chemically very reactive.
  5. form ionic bonds in aqueous solutions.





Answer: 3







Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that

Naim 02:20

Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that





  1. the atom would become a positively charged ion, or cation.
  2. an electron may move to an electron shell closer to the nucleus.
  3. an electron may move to an electron shell farther out from the nucleus.
  4. the atom may become a radioactive isotope.
  5. the atom would become a negatively charged ion, or anion.






Answer: C

One difference between carbon-12 (126C) and carbon-14 (146C) is that carbon-14 has

Naim 02:20

One difference between carbon-12 (126C) and carbon-14 (146C) is that carbon-14 has




A) two more neutrons than carbon-12.
B) two more electrons than carbon-12.
C) two more protons than carbon-12.
D) two more protons than carbon-12 and two more neutrons than carbon-12.
E) two more electrons than carbon-12 and two more neutrons than carbon-12.







Answer: A

About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?

Naim 02:19

About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?



a. oxygen, hydrogen, calcium, sodium
b. carbon, hydrogen, nitrogen, oxygen
c. carbon, sulfur, phosphorus, hydrogen
d. carbon, sodium, chlorine, nitrogen
e. carbon, oxygen, sulfur, calcium





Answer: B

Which of the following describes any reaction that has reached chemical equilibrium?

Naim 02:18

Which of the following describes any reaction that has reached chemical equilibrium?





A) All of the reactants have been converted to the products of the reaction.
B) The rate of the forward reaction is equal to the rate of the reverse reaction.
C) The concentration of the reactants equals the concentration of the products.
D) All of the products have been converted to the reactants of the reaction.
E) Both the forward and the reverse reactions have stopped with no net effect on the concentration of the reactants and the products.







Answer: B

What is the difference between covalent bonds and ionic bonds?

Naim 02:17

What is the difference between covalent bonds and ionic bonds?




A) Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of electrons between atoms.

B) Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atoms.

C) Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of neutrons between atoms.

D) Covalent bonds involve the transfer of electrons between atoms, and ionic bonds involve the sharing of neutrons between atoms.

E) Covalent bonds involve the sharing of neutrons between atoms, and ionic bonds involve the sharing of electrons between atoms.







Answer: B

A frameshift mutation could result from

Naim 21:32

A frameshift mutation could result from





a. a base insertion only.

b. a base deletion only.

c. a base substitution only.

d. deletion of three consecutive bases.

e. either an insertion or a deletion of a base.








Answer: E

With each replication of the DNA molecule, the DNA molecule becomes shorter.

Naim 21:31

With each replication of the DNA molecule, the DNA molecule becomes shorter.




a. This is best explained by the fact that DNA polymerase can only add nucleotides to the 5' end

b. This problem is resolved by telomerase, which extends the 3' end of the DNA

c. This is not a problem because the telomere is a nonessential repeating unit

d. This is true only if the organism has been exposed to excessive amounts of ultraviolet radiation

e. This is due to the fact that thymine dimers cause DNA to buckle and interfere with DNA replication







Answer: B

In DNA, the designations 3' and 5' refer to the

Naim 21:31

In DNA, the designations 3' and 5' refer to the






a. bonds formed between phosphate groups and carbon atoms of deoxyribose.

b. carbon or nitrogen atoms on the rings of purine or pyrimidines.

c. cross-linking of the third and fifth carbon atoms of deoxyribose.

d. bonding between purines and deoxyribose and between pyrimidines and deoxyribose.

e. bonds that form between adenine and thymine and between guanine and cytosine.







Answer: A

The 3' Poly-A tail is attached to

Naim 21:31

The 3' Poly-A tail is attached to




a. the Poly-A polymerase enzyme.

b. the mRNA.

c. the tRNA.

d. the coding strand of the DNA molecule.

e. the template strand of the DNA molecule.








Answer: B

DNA polymerase requires a(n)

Naim 21:27

DNA polymerase requires a(n)




a. amino acid primer.

b. lipid primer.

c. hydrophilic primer.

d. DNA primer.

e. RNA primer.





Answer: E

Hershey-Chase concluded from their experiment with T2 bacteriophage that

Naim 21:27

Hershey-Chase concluded from their experiment with T2 bacteriophage that





a. proteins are the genetic material.

b. polysaccharide coat contains the genetic material.

c. DNA is the genetic material.

d. viruses are needed for DNA to function.

e. DNA contains sulfur.







Answer: C

A man who had purple ears came to the attention of a human geneticist. The human geneticist did a pedigree analysis and made the following observations: In this family, purple ears proved to be an inherited trait due to a single genetic locus. The man's mother and one sister also had purple ears, but his father, his brother, and two other sisters had normal ears. The man and his normal-eared wife had seven children, including four boys and three girls. Two boys and two girls had purple ears. The purple-ear trait is most probably

Naim 21:25

A man who had purple ears came to the attention of a human geneticist. The human geneticist did a pedigree analysis and made the following observations:
In this family, purple ears proved to be an inherited trait due to a single genetic locus. The man's mother and one sister also had purple ears, but his father, his brother, and two other sisters had normal ears. The man and his normal-eared wife had seven children, including four boys and three girls. Two boys and two girls had purple ears. The purple-ear trait is most probably




a. autosomal, dominant

b. autosomal, recessive

c. sex-linked, dominant

d. sex-linked, recessive

e. cannot be determined from this information









Answer: A

Coat color in mice is determined by genes at two loci. When black mice from a particular population of mate, they produce offspring in the following ratios: 9 black: 3 brown: 4 white. These results suggest that white coat color is expressed as a result of

Naim 21:25

Coat color in mice is determined by genes at two loci. When black mice from a particular population of mate, they produce offspring in the following ratios: 9 black: 3 brown: 4 white. These results suggest that white coat color is expressed as a result of



a. Dominance

b. Incomplete dominance

c. Codominance

d. A sex-linked trait

e. Epistasis





Answer: E

A couple has three children, all of whom have brown eyes and blond hair. Both parents are homozygous for brown eyes (BB), but one is a blond (rr) and the other is a redhead (Rr). What is the probability that their next child will be a brown eyed redhead?

Naim 21:24

A couple has three children, all of whom have brown eyes and blond hair. Both parents are homozygous for brown eyes (BB), but one is a blond (rr) and the other is a redhead (Rr). What is the probability that their next child will be a brown eyed redhead?



a. 1/16

b. 1/8

c. 1/4

d. 1/2

e. 1







Answer: D

In the fruit fly Drosophila, the allele for normal body (B) is dominant to the allele for hairy body (b). When two normal bodied fruit flies were mated, they produced 81 hair-bodied flies and 319 normal -bodied flies. The genotypes of the parents are most likely?

Naim 21:24

In the fruit fly Drosophila, the allele for normal body (B) is dominant to the allele for hairy body (b). When two normal bodied fruit flies were mated, they produced 81 hair-bodied flies and 319 normal -bodied flies. The genotypes of the parents are most likely?



a. BB x bb

b. BB x Bb

c. Bb x Bb

d. Bb x bb

e. bb x bb








Answer: C


Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of

Naim 21:23

Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of



a. codominance.

b. incomplete dominance.

c. epistatic interaction.

d. blending.








Answer: B
Subscribe to: Posts (Atom)