Chapter 14 MicroBiology Homework Review

The ATP synthase can be thought of as a type of molecule motor that is powered by the flow of ____________ through the subunits and __________ their concentration gradient. Choose one: A. e- / down B. H+ / down C. H+ / up D. e- / up

B. H+ / down

Energy from cellular metabolism is converted to ATP by respiring organisms. Place the following steps in the correct order. -Glycolysis and TCA cycle generate NADH & FADH. -NADH and FADH are oxidized by electron transport proteins. -Electron transport releases energy that is used to translocate H+. -An electrochemical gradient of protons is established (Δp). -Influx of H+ through ATP synthase drives ATP production.

1 Glycolysis and TCA cycle generate NADH & FADH. 2 NADH and FADH are oxidized by electron transport proteins. 3 Electron transport releases energy that is used to translocate H+. 4 An electrochemical gradient of protons is established (Δp). 5 Influx of H+ through ATP synthase drives ATP production.

For every 2 molecules of water consumed, the light reactions of oxygenic photosynthesis generate ________ molecule(s) of ATP, ________ molecule(s) of NADPH, and _________ molecule(s) of O2.

3,2,1

Mitochondrial electron transport systems are able to translocate up to 12 H+ per NADH. What is the corresponding maximum theoretical yield of ATP?

4 ATP

If an oxygenic phototroph (such as a marine cyanobacterium) has sufficient quantities of ________, cyclic flow of electrons back to the ________ reaction center can provide energy for the generation of _________ instead. Choose one: A. NAD(P)H; PSI; ATP B. ATP; PSI; NAD(P)H C. ATP; PSII; NAD(P)H D. NAD(P)H; PSII; ATP

A. NAD(P)H; PSI; ATP

Identify the oxidant in the following coupled redox reaction: Malate + NAD+ → Oxaloacetate + NADH + H+ Choose one: A. NAD+ B. NADH C. malate D. oxaloacetate

A. NAD+

Hydrogenotrophs use H2 in what way? Choose one: A. as a source of energy and electrons B. as a terminal electron acceptor C. as a way to dump electrons in fermentation D. for buoyancy in aquatic habitats E. to fix carbon autotrophically

A. as a source of energy and electrons

Because the reduction potential of the CO2/glucose redox pair is more negative than the Fe3+/Fe2+ redox pair, energy is released as electrons flow Choose one: A. from glucose (the donor) to Fe3+ (the acceptor). B. from CO2 (the donor) to Fe3+ (the acceptor). C. from Fe2+ (the donor) to CO2 (the acceptor). D. from glucose (the donor) to Fe2+ (the acceptor). E. from Fe2+ (the donor) to glucose (the acceptor).

A. from glucose (the donor) to Fe3+ (the acceptor).

What is the minimum number of NADH molecules that must be oxidized for oxygen to be reduced to water? Choose one: A. 1 B. 2 C. 3 D. None; the electrons to reduce water are picked up free from the cytoplasm.

B. 2

Nitrifiers obtain energy from which of the following? Choose one: A. using nitrate as a terminal electron acceptor in anaerobic respiration B. the aerobic oxidation of ammonia and nitrite C. using nitrite as a terminal electron acceptor in anaerobic respiration D. the anaerobic oxidation of ammonia using nitrite E. the aerobic oxidation of nitrate

B. the aerobic oxidation of ammonia and nitrite

Cyanobacteria are the only prokaryotic phototrophs that Choose one or more: A.create a Δp from the flow of photoexcited electrons. B.evolve oxygen as a result of photolysis. C.have both PSII and PSI. D.can use H2O as an electron donor. E.can fix CO2 into biomass. F.can use photoexcited electrons to reduce NAD(P)+.

B.evolve oxygen as a result of photolysis. C.have both PSII and PSI. D.can use H2O as an electron donor.

During ATP synthesis, the energy in the Δp is used to drive the physical rotation of which portion(s) of the enzyme? Choose one or more: A.the alpha and beta subunits of the F1 portion B.the gamma subunit connecting Fo and F1 C.the c subunits of the Fo portion D.the a and b subunits connecting F1 to the membrane

B.the gamma subunit connecting Fo and F1 C.the c subunits of the Fo portion

In addition to these archaea, many bacteria in marine surface waters also use phototrophy to augment the sometimes limited energy they gain from heterotrophy. In bacteria, however, the light-driven pumps are referred to as which of the following? Choose one: A. phycoerythrin B. bacteriochlorophyll C. proteorhodopsin D. phycocyanin E. carotenoids

C. proteorhodopsin

In photoautotrophs, the chemical energy produced by the "light" reactions (i.e., photolysis and electron transport) is used to fuel which cellular process? Choose one: A. fermentation B. reverse electron transport C. TCA cycle D. carbon fixation E. glycolysis

D. carbon fixation

All of the following types of metabolism use a membrane-associated electron transport system (ETS) EXCEPT for Choose one: A. lithotrophy. B. phototrophy. C. mitochondrial respiration. D. fermentation. E. organotrophy.

D. fermentation.

The video explains how O2 becomes reduced to H2O during aerobic respiration. In the example of the bacterial ETS that was given, how many protons were actually lost from the cytoplasm for every O2 molecule that was consumed? Choose one: A. 16 B. 8 C. 4 D. 28 E. 20

E. 20

Which of the following atmospheric gases is produced from the reduction of an alternative terminal electron acceptor in microbial respiration? Choose one: A. helium B. CO2 C. O2 D. water vapor E. N2

E. N2

What is the terminal electron acceptor in oxygenic photosynthesis?Choose one: A. oxygen B. water C. quinone D. ATPE. NADP+

E. NADP+

Halohasta litchfieldiae is a photoheterotroph, meaning that unlike the algae in the lake, it does not fix CO2. It does, however, use light energy to supplement the energy it derives from oxidation of organic carbon. It is able to do this by directly coupling light energy to extrusion of ________________ across the membrane.

Hydrogen Ions

Sort the list of substrates below depending on whether they act as electron donors in lithotrophy or organotrophy. Substrates (10 items) (Drag and drop into the appropriate area below) -Hydrogen -Elemental sulfur -Methane -Carbon monoxide -Ferrous iron -Ammonia -Gluconate -Fatty acids -Glycerol Fructose

Lithotrophy Hydrogen Elemental sulfur Methane Carbon monoxide Ferrous iron Ammonia Organotrophy Gluconate Fatty acids Glycerol Fructose

Arrange the following items in the order in which they receive electrons from glycolysis and TCA oxidations and harness the energy to establish a transmembrane proton gradient. Events (5 items) (Drag and drop into the appropriate area) No more items Order of Events NAD+ Oxidoreductase Quinone Terminal oxidase Oxygen

Order of Events 1-NAD+ 2-Oxidoreductase 3-Quinone 4-Terminal oxidase 5-Oxygen

Many of the redox centers that comprise the electron transport system (ETS) are integral components of larger protein complexes, whereas others, such as _______________, freely diffuse within the membrane as they ferry electrons between other ETS components.

quinones