Deck 10: Catabolism Energy Release and Conservation

Question 1

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

Answer 1

C

Question 2

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 2

True

Question 3

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

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

Answer 3

C

Question 4

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 5

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

Question 6

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

Question 7

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

Question 8

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 9

The pentose phosphate pathway produces

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

Question 10

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 11

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

Question 12

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 13

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) one ATP molecule.

Question 14

__________ pathways are those that function both catabolically and anabolically.

Question 15

____________ ____________ 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.

Question 16

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 17

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

Question 18

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 19

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

Question 20

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

Question 21

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

Question 22

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

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

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 25

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 26

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

Question 27

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

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.

Question 29

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

Question 30

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 31

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

Question 32

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 33

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 34

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 35

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 36

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 37

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

Question 38

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

Question 39

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

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

Fatty acids are metabolized by the __________ pathway.

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

Question 42

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 43

_______________ 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 44

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

Question 45

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

Question 46

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 47

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 48

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

Question 49

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

Question 50

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 51

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 52

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 53

All eukaryotic photosynthesizers are oxygenic.

Question 54

All prokaryotic photosynthesizers are anoxygenic.

Question 55

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 56

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 57

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

Question 58

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

Question 59

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 60

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

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.