Chapter 11

Select the terms that describe an organism's carbon source. _____ Heterotroph _____ Lithotroph _____ Chemotroph _____ Autotroph _____ Organotroph

Heterotroph, Autotroph

Which of the following names refer to the tricarboxlic acid cycle? _____ Krebs cycle _____ Pentose phosphate pathway _____ Calvin cycle _____ Citric acid cycle _____ Cyclic phosphorylation

Kreps cycle, Citric acid cycle

Differences between mitochondrial and E. coli electron transport chains include the following: A. The E. coli chain contains a different array of cytochromes. B. The fundamental principles on which they operate are different. C. Higher P/O values are observed in E. coli. D. The electron transport chain does not involve membranes in E. coli.

a

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

a

In most cases, fueling reactions are__________reactions. A. catabolic B. anabolic C. reducing D. synthesizing

a

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

a

The TCA cycle is located in the ______________ of bacteria, and in the _____________ of eukaryotes. A. cytoplasm; mitochondrial matrix B. plasma membrane; inner mitochondrial membrane C. plasma membrane; mitochondrial matrix D. cytoplasm; inner mitochondrial membrane

a

The terms phototroph and chemotroph refer to an organism's source of A. energy. B. electrons. C. carbon. D. nitrogen.

a

Chlorophyll a and chlorophyll b as well as the accessory pigments are arranged in an antenna array with a reaction center chlorophyll. These antenna arrays with the reaction center chlorophyll are known as A. reaction center systems. B. photomembrane systems. C. photosystems. D. Calvin systems.

c

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

c

During glycolysis, ATP is produced when 1,3 bisphosphoglycerate transfers a phosphate to ADP forming ATP. This is an example of A. photophosphorylation. B. oxidative phosphorylation. C. substrate-level phosphorylation. D. glycolytic phosphorylation.

c

How does a fermenter generate proton motive force (PMF) to drive active transport? A. Fermenters use an electron transport chain for this purpose. B. Fermenters cannot generate proton motive force. C. Fermenters can reverse the direction of the ATP synthase to generate PMF.

c

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.

c

In order for a substance to transfer a phosphate to ADP in a substrate-level phosphorylation reaction, which of the following must be true? A. The phosphate donor must have a lower phosphate transfer potential than ATP. B. The phosphate donor must have a higher oxidation-reduction potential than ATP. C. The phosphate donor must have a higher phosphate transfer potential than ATP. D. The phosphate donor must have a lower oxidation-reduction potential than ATP.

c

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

c

The most common pathway for conversion of glucose to pyruvate is A. Entner-Doudoroff. B. Pentose phosphate. C. Embden-Meyerhoff. D. mixed acid fermentation.

c

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.

c

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.

c

The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO2 and A. lactate. B. isocitric acid. C. acetyl-CoA. D. succinyl-CoA.

c

The sum total of all chemical reactions occurring in a cell is called A. anabolism. B. catabolism. C. metabolism. D. None of the choices are correct.

c

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

c

The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is A. 2. B. 32. C. 38. D. 85.

c

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.

c

The six carbons of the glucose molecule that enter the cell respiration pathway end up in/as _______ ______ by the end of the process.

carbon dioxide

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

chemiosmotic

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

chemiosmotic

A newly described bacterial species has been shown to use CO2 as its carbon source. Its energy source and its source of reducing power (electrons) are inorganic chemicals. Which term would best describe this nutritional type? A. Chemolithoheterotroph B. Photoorganoheterotroph C. Photolithoheterotroph D. Chemolithoatotroph

d

Amino acids are processed first by the removal of the amino group through A. deamination. B. transamination. C. phosphorolytic cleavage. D. deamination or transamination.

d

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

d

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 are correct.

d

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.

d

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.

d

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.

d

The pentose phosphate pathway produces A. CO2. B. NADPH. C. glyceraldehyde 3-phosphate. D. All of the choices are correct.

d

What distinguishing feature characterizes aerobic and anaerobic respiration but does not play a role in fermentation pathways? A. Oxidation-reduction reactions B. Hydrolysis reactions C. The absence of O2 D. The presence of an electron transport chain

d

When nitrate is used as a final electron acceptor by bacteria growing in anoxic soils, the nitrogen is no longer available for the construction of precursor metabolites. This is referred to as A. nitrification. B. nitrogen fixation. C. nitrogen respiration. D. dissimilatory nitrate reduction.

d

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 are correct.

d

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 are correct.

d

Which of the following produces the most ATP during aerobic respiration? A. Glycolysis B. TCA cycle C. Fermentation D. Electron transport chain and chemiosmosis E. Susbstrate level phosphorylation

d

____________ is an aerobic chemolithotrophic process that ultimately oxidizes ammonia to nitrate, whereas __________ is a form of anaerobic respiration involving the oxidation of an organic compound using an oxidized nitrogenous compound, such as nitrate, as the terminal electron acceptor. A. Ammonification; nitrification B. Denitrification; nitrification C. Ammonification; denitrification D. Nitrification; denitrification

d

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.

dissimilatory

A _________ hydrolyzes a protein into its constituent amino acid monomers and a ___________enzyme removes amino groups from the amino acids.

protease; deaminase

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

proteases

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

pyruvate dehydrogenase

Whereas the Embden-Meyerhof pathway produces two molecules of pyruvate (net) for each glucose, the Entner-Doudoroff pathway produces one molecule each of ___________ and ____________.

pyruvate; glyceraldehyde (or Alternative answer: glyceraldehyde; pyruvate)

Which of the following are consequences of anaerobic respiration? (Check all that apply.) __1__ Some bacteria are able to readily survive in both well-oxygenated as well as anoxic environments. __2__ Some bacteria may cause denitrification. __3__ Some bacteria are able to perform nitrogen fixation. __4__ Bacteria are able to reduce the levels of NO3 ¯ in sewage plant effluents.

1, 2, 4

Which of the following described roles attributed to accessory pigments such as carotenes and phycobiliproteins? (Check all that apply.) __1__ These pigments absorb light in ranges not absorbed by chlorophylls and transfer the energy to chlorophylls. __2__ These pigments extend the spectrum of wavelengths that will drive photosynthesis. __3__ The accessory pigments are involved in maintaining the Calvin cycle. __4__ Accessory pigments protect organisms from potentially damaging intense sunlight

1, 2, 4

In what ways are oxidative phosphorylation and photophosphorylation similar? __1__ The source of energy is highly reduced organic compounds __2__ An electron transport chain is used __3__ Proton motive force is generated __4__ Water is split to provide electrons __5__ ATP synthase enzyme phosphorylates ADP to make ATP

2, 3, 5

Indicate the processes below that represent the basic types of chemoorganotrophic metabolism. __1__ Photosynthesis __2__ Aerobic respiration __3__ Fermentation __4__ Oxidation-reduction __5__ Anaerobic respiration

2, 3, 5

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.

3

Photoheterotrophs that use light to generate ATP, but do not fix CO2 (Check all that apply.) __1__ would best be described as photosynthetic. __2__ would use both the light reactions and the Calvin cycle. __3__ would use neither the light reactions nor the Calvin cycle. __4__ would best be described as phototropic. __5__ would use the light reactions but not the Calvin cycle.

4, 5

____________ ____________ 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.

Aerobic respiration

__________ pathways are those that function both catabolically and anabolically.

Amphibolic

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

Nitrification

Consider the metabolism of a chlorophyll-based phototroph. In oxidative phosphorylation during cell respiration, the source of energy is ______________ whereas in photophosphorylation the source of energy is ____________. A. highly reduced organic compounds; light B. NADH; NADPH C. electron transport chain; chlorophyll D. ATP; light

a

Indicate the products of aerobic respiration. _____ Water _____ O2 _____ CO2 _____ NADH _____ ATP _____ All of the choices are correct.

Water, CO2, ATP

Aerobic respiration, anaerobic respiration, and fermentation are the three basic types of A. chemoorganoheterotrophic metabolism. B. photolithoautotrophic metabolism. C. chemolithoautotrophic metabolism. D. chemoorganoautotrophic metabolism.

a

Complete catabolism of lactose requires A. ATP, NAD, and appropriate enzymes. B. ATP, UTP, NAD, and appropriate enzymes. C. NAD and appropriate enzymes.

b

Fatty acids are metabolized by the __________ pathway. A. alpha-oxidation B. beta-oxidation C. gamma-oxidation D. delta-oxidation

b

How is ATP produced during fermentation? A. Cyclic phosphorylation B. Substrate-level phosphorylation C. Oxidative phosphorylation D. Use of proton motive force to drive ATP synthase E. Chemosynthetic phosphorylation

b

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

b

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

b

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

b

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.

b

Processes that supply ATP, reducing power, and precursor metabolites are collectively referred to as ____________ reactions. A. redox B. fueling C. synthetic D. generating

b

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.

b

The amount of ATP produced during anaerobic respiration is ___________ that produced during aerobic respiration, because the difference in the standard reduction potential between NADH and the final electron acceptor is _______________. A. less than; larger B. less than; smaller C. greater than; larger D. greater than; smaller

b

The substances that donate electrons to the electron transport chains of chemolithotrophs are ___________. A. carbohydrates B. inorganic compounds C. lipids D. methane gas and alcohols

b

What enzymes hydrolyze proteins, releasing amino acids? A. Tranaminases B. Proteases C. Decarboxylases D. Deaminases

b

Which nutritional classification would you predict to fit most of the well-known members of the human microbiome? A. Photolithoautotrophs B. Chemoorganoheterotrophs C. Chemolithoautotrophs D. Chemolithohetertrophs

b

Which of the following is produced in largest numbers by the TCA cycle? A. ATP (GTP) B. NADH C. FADH D. CO2

b

Which of the following is the major glycolytic pathway used by plants and animals? A. Tricarboxylic acid cycle B. Embden-Meyerhof pathway C. Entner-Doudoroff pathway D. Pentose phosphate pathway

b

______________ refers to the removal of an amino group from an amino acid. One mechanism for this removal is _____________, in which the amino group is transferred to an acceptor molecule. A. Deamination; hydrolysis B. Deamination; transamination C. Transamination; deamination D. Hydrolysis; transamination

b

Chemolithotrophs generally derive ________ ATP from oxidation of inorganic substrates because the reduction potentials of those substrates are much more ________ than the reduction potential of organic substrates. A. more; positive B. more; negative C. less; positive D. less; negative

c

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

mitochondrial matrix

How does the phosphorylation of galactose differ from the phosphorylation of glucose, mannose, and fructose prior to catabolism? A. Phosphorylation of galactose requires NADPH to phosphorylate galactose-1-phosphate B. Phosphorylation of galactose requires PEP (phosphoenolpyruvate) to phosphorylate galactose-1-phosphate C. Phosphorylation of galactose requires ATP to phosphorylate galactose-1-phosphate D. Phosphorylation of galactose requires TTP to phosphorylate galactose-1-phosphate E. Phosphorylation of galactose requires UTP to phosphorylate galactose-1-phosphate

e

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

heterolactic

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

homolactic

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

hydrolysis; phosphorolysis

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

hydrolytic enzymes