Chapter 10 Microbiology

____________ ____________ 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. (2 words)  

After glycolysis, pyruvate is oxidized to one CO2 and the two-carbon molecule acetyl-CoA by a multienzyme system called the ________ ________ complex. (2 words)  

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

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

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

Large external polysaccharides are degraded by bacteria and archaea using ________ ________, which secrete these substances outside the cell. (2 words)  

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

TCA cycle enzymes are found in the _____________ _________ of eukaryotic cells. (2 words)  

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

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.  

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.  

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

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

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

• True

• False

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.  

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

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

• Anabolism

• Catabolism

• Metabolism

• None of the choices

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

• True

• False

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

• Lactate

• Isocitric acid

• Acetyl-CoA

• Succinyl-CoA

Fatty acids are metabolized by the __________ pathway.  

• Alpha-oxidation

• Beta-oxidation

• Gamma-oxidation

• Delta-oxidation

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

• Hydrogen gas

• Reduced nitrogen compounds

• Reduced sulfur compounds

• All of the choices

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

• 2

• 36

• 38

• 85

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

• More

• Less

• The same amount of

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

• Nitrate

• Sulfate

• Carbon dioxide

• All of the choices

All prokaryotic photosynthesizers are anoxygenic.  

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

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

• Acetyl-CoA

• Ethanol

• Carbon dioxide

• Methanol

All eukaryotic photosynthesizers are oxygenic.  

• True

• False

The pentose phosphate pathway produces  

• CO2

• NADPH

• Glyceraldehyde 3-phosphate

• All of the choices

Mitochondrial electron transport takes place  

• On the outer mitochondrial membrane.

• On the inner mitochondrial membrane.

• In the fluid matrix of the mitochondria.

• On the outer mitochondrial membrane and on the inner mitochondrial membrane

The most common pathway for conversion of glucose to pyruvate is  

• Entner-Doudoroff

• Pentose phosphate

• Embden-Meyerhoff

• Mixed acid fermentation

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

• True

• False

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  

• Utilization ratio

• Energy yield

• P/O ratio

• Phosphorylation coefficient

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

• Chemiosmotic

• Oxidative

• Substrate level

• Conformational change

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

• Energy production

• Provision of carbon skeletons for biosynthesis of cell components.

• Electron transport.

• Energy production and provision of carbon skeletons for biosynthesis of cell components.

Differences between mitochondrial and E. coli electron transport chains include the following:  

• The E. coli chain contains a different array of cytochromes.

• The fundamental principles on which they operate are different.

• Higher P/O values are observed in E. coli.

• The electron transport change does not involve membranes in E. coli.

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.  

• Photosynthesis

• Cyclic photophosphorylation

• Acyclic photophosphorylation

• Noncyclic photophosphorylation

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

• One; carbon dioxide

• One; methane

• Two; acetyl-CoA

• Two; ethanol

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?  

• 2

• 3

• 4

• 10-12

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

• Acetyl-CoA

• Ethanol

• Carbon dioxide

• Methanol

In the process of noncyclic photophosphorylation  

• Water is split to form oxygen gas.

• Electrons from water flow through electron transport chains resulting in synthesis of ATP and NADPH.

• Photosystems I and II are both required.

• All of the choices