Deck 11: Catabolism: Energy Release and Conservation

Question 1

____________ ____________ is a process that can completely catabolize an organic energy source to CO₂ using the glycolytic pathways and TCA cycle with O₂ as the terminal electron acceptor for an electron transport chain.

Answer 1

aerobic respiration

Question 2

An organism may use glycolysis and the pentose phosphate pathway simultaneously.

Answer 2

True

Question 3

Although most metabolic reactions are freely reversible,a few irreversible catabolic steps are bypassed during biosynthesis with special enzymes that catalyze the reverse reaction in order to allow for independent regulation of catabolic and anabolic pathways.

Answer 3

True

Question 4

In the TCA cycle,two carbons are removed from citric acid in the form of __________,thereby regenerating oxaloacetate to complete the cycle.

A)acetyl-CoA
B)ethanol
C)carbon dioxide
D)methanol

Question 5

__________ pathways are those that function both catabolically and anabolically.

Question 6

The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhoff pathway in prokaryotes is

A)2.
B)36.
C)38.
D)85.

Question 7

In the TCA cycle,two carbons in the form of __________ are added to oxaloacetate at the start of the cycle.

A)acetyl-CoA
B)ethanol
C)carbon dioxide
D)methanol

Question 8

The most common pathway for conversion of glucose to pyruvate is

A)Entner-Doudoroff.
B)Pentose phosphate.
C)Embden-Meyerhoff.
D)mixed acid fermentation.

Question 9

The TCA cycle generates all of the following from each acetyl-CoA molecule oxidized except

A)three NADH molecules.
B)two CO₂ molecules.
C)one FADH₂ molecule.
D)two ATP or GTP molecules.

Question 10

Very few gram positive bacteria utilize the Entner-Doudoroff glycolytic pathway.

Question 11

The pentose phosphate pathway produces

A)CO₂.
B)NADPH.
C)glyceraldehyde 3-phosphate.
D)all of the choices.

Question 12

After glycolysis,pyruvate is oxidized to one CO₂ and the two-carbon molecule acetyl-CoA by a multienzyme system called the ________ ________ complex.

Question 13

Some aerobic bacteria lack the Entner-Doudoroff and Embden-Meyerhoff pathways and instead use the pentose phosphate pathway for glycolysis.

Question 14

Metabolic pathways can be either catabolic or anabolic but not both.

Question 15

The sum total of all chemical reactions occurring in a cell is called

A)anabolism.
B)catabolism.
C)metabolism.
D)none of the choices

Question 16

The synthesis of ATP from ADP and Pi,when coupled with an exergonic chemical reaction is called __________ phosphorylation.

A)chemiosmotic
B)oxidative
C)substrate-level
D)conformational change

Question 17

The net gain of ATP per molecule of glucose metabolized to pyruvate using Entner-Doudoroff pathway is

A)4.
B)2.
C)1.
D)0.

Question 18

The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO₂ and

A)lactate.
B)isocitric acid.
C)acetyl-CoA.
D)succinyl-CoA.

Question 19

TCA cycle enzymes are found in the _____________ _________ of eukaryotic cells.

Question 20

The catabolism of glucose begins with one or more of the glycolytic pathways that yield pyruvate.

Question 21

When cells of a facultative anaerobe such as Paracoccus denitrificans are growing under anaerobic conditions and using nitrate as the terminal electron acceptor,______________ nitrate reduction is occurring.

Question 22

The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH)to O₂ is called the

A)utilization ratio.
B)energy yield.
C)P/O ratio.
D)phosphorylation coefficient.

Question 23

In aerobic conditions,it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.

A)more
B)less
C)the same amount of

Question 24

Fermentation involves the use of pyruvate and/or other organic molecules as electron acceptors.

Question 25

The hypothesis that proton motive force drives ATP synthesis is called the __________ hypothesis.

Question 26

Bacterial electron transport chains may be comprised of fewer components and have lower P/O ratios than mitochondrial transport chains.

Question 27

Prokaryotes may use several different terminal oxidases for the electron transport system.

Question 28

In higher eukaryotes,most aerobically generated ATP is produced by

A)glycolysis.
B)the TCA cycle.
C)a membrane bound proton translocating ATP synthase during oxidative phosphorylation.
D)all of these generate equal amounts of ATP.
ASM

Question 29

The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is

A)2.
B)32.
C)38.
D)85.

Question 30

The electron transport systems in eukaryotes and prokaryotes use different electron carriers.

Question 31

When mitochondria pass electrons donated by NADH through the electron transport chain to molecular oxygen,a theoretical maximum of __________ molecules of ATP can be made per oxygen molecule reduced.

Question 32

Reduction of nitrate to nitrite by Paracoccus denitrificans is an example of anaerobic respiration.

Question 33

The most commonly accepted hypothesis for the production of ATP that results from electron transport system is called the __________ hypothesis.

Question 34

Production of ATP using the energy liberated when electrons from reduced chemical bonds are passed through the electron transport system is generally referred to as __________.

A)chemiosmotic
B)respiration
C)substrate-level
D)conformational change

Question 35

The major function(s)of the TCA cycle is(are)

A)energy production.
B)provision of carbon skeletons for biosynthesis of cell components.
C)electron transport.
D)energy production and provision of carbon skeletons for biosynthesis of cell components.

Question 36

Which of the following is NOT true regarding ATP synthases?

A)They require proton motive force to make ATP.
B)They span the inner membrane of mitochondria.
C)The proton flow is outward during ATP synthesis.
D)The subunits of ATP synthase undergo conformational changes during ATP production.

Question 37

In addition to being used in the making of ATP,proton motive force is used directly to power the rotation of bacterial flagella.

Question 38

Which of the following can be used as electron acceptors during anaerobic respiration?

A)nitrate
B)sulfate
C)carbon dioxide
D)all of the choices

Question 39

Organisms that form lactate,ethanol,and CO₂ as end products of glucose metabolism are called __________ fermenters.

Question 40

Mitochondrial electron transport takes place

A)on the outer mitochondrial membrane.
B)on the inner mitochondrial membrane.
C)in the fluid matrix of the mitochondria.
D)on the outer mitochondrial membrane and on the inner mitochondrial membrane.

Question 41

In the process of __________,ATP is synthesized when excited electrons from chlorophyll P700 pass through a series of electron carriers then return to chlorophyll P700.

A)photosynthesis
B)cyclic photophosphorylation
C)acyclic photophosphorylation
D)noncyclic photophosphorylation

Question 42

Organisms that directly reduce almost all of their pyruvate to lactate are called __________ fermenters.

Question 43

Proteins are catabolized by hydrolytic cleavage to amino acids by the action of enzymes called __________.

Question 44

How many molecules of ATP are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis?

A)2
B)3
C)4
D)10-12

Question 45

Amino acids are processed first by the removal of the amino group through

A)deamination.
B)transamination.
C)phosphorolytic cleavage.
D)deamination or transamination

Question 46

All prokaryotic photosynthesizers are anoxygenic.

Question 47

How many quanta of light are needed to reduce one molecule of carbon dioxide to carbohydrate during photosynthesis?

A)2
B)3
C)4
D)10-12

Question 48

Which of the following may be used as sources of energy by chemolithotrophs?

A)Hydrogen gas.
B)Reduced nitrogen compounds.
C)Reduced sulfur compounds.
D)All of the choices.

Question 49

All eukaryotic photosynthesizers are oxygenic.

Question 50

Large external polysaccharides are degraded by bacteria and archaea using ________ ________,which secrete these substances outside the cell.

Question 51

How many molecules of NADPH are needed to reduce one molecule of carbon dioxide to carbohydrate by oxygenic phototrophs during the dark reactions of photosynthesis?

A)2
B)3
C)4
D)10-12

Question 52

In the process of noncyclic photophosphorylation

A)water is split to form oxygen gas.
B)electrons from water flow through electron transport chains resulting in synthesis of ATP and NADPH.
C)photosystems I and II are both required.
D)all of the choices

Question 53

Nitrification of ammonia occurs when ammonia is first converted to nitrite and then is converted to nitrate by the nitrogen-fixing bacteria.

Question 54

_______________ is a two-step process that depends on the activity of at least two genera to carry out the oxidation of ammonia to nitrate.

Question 55

Oxygen is always required for the regeneration of NAD from NADH.

Question 56

During breakdown of fatty acids,carbons are removed __________ at a time with each turn of the cycle,and two carbon units are released as __________.

A)one; carbon dioxide
B)one; methane
C)two; acetyl-CoA
D)two; ethanol

Question 57

Fatty acids are metabolized by the __________ pathway.

A)alpha-oxidation
B)beta-oxidation
C)gamma-oxidation
D)delta-oxidation

Question 58

Photosynthetic organisms serve as the base for most food chains in the biosphere.

Question 59

Disaccharides and polysaccharides can be processed as nutrients after first being cleaved to monosaccharides by either __________ or __________.

Question 60

In the process of fermentation an organic substrate,such as glucose,is reduced and an intermediate of the pathway,such as pyruvate,is oxidized.

Question 61

Photosynthetic electron transport in cyanobacteria takes place

A)on the plasma membrane.
B)in the chloroplast.
C)in the cytoplasm.
D)on the thylakoid membranes.