Question 1

All of the following are reasons to oxidize glucose in a series of steps EXCEPT to

Accepted Answer

A)  generate smaller amounts of energy in a controlled fashion and when needed. 
B)  control the usage of energy in a cell by using more steps. 
C)  minimize the release of heat with more small steps. 
D)  control the catabolism versus biosynthetic aspects of oxidizing glucose via concentrations of reactants and end products. 
E)  increase the DG of the reaction. 
A)  generate smaller amounts of energy in a controlled fashion and when needed. 
B)  control the usage of energy in a cell by using more steps. 
C)  minimize the release of heat with more small steps. 
D)  control the catabolism versus biosynthetic aspects of oxidizing glucose via concentrations of reactants and end products. 
E)  increase the DG of the reaction.

Question 2

The base adenine forms from ________ in experiments simulating the origin of life on Earth.

Accepted Answer

A)  carbon dioxide and nitrate 
B)  ethanol and urea 
C)  methane and ammonia 
D)  adenosine and PO4 
E)  ribose and RNA 
A)  carbon dioxide and nitrate 
B)  ethanol and urea 
C)  methane and ammonia 
D)  adenosine and PO4 
E)  ribose and RNA

Question 3

Bacteria synthesize ribose for nucleotides using which pathway?

Accepted Answer

A)  Embden-Meyerhof-Parnas 
B)  Entner-Doudoroff 
C)  pentose phosphate shunt 
D)  tricarboxylic acid cycle 
E)  electron transport system 
A)  Embden-Meyerhof-Parnas 
B)  Entner-Doudoroff 
C)  pentose phosphate shunt 
D)  tricarboxylic acid cycle 
E)  electron transport system

Question 4

Escherichia coli degrades human waste in the colon using mixed-acid fermentation. Why is this a factor of concern in some medical procedures, such as colonoscopy?

Accepted Answer

Molecular hydrogen (H₂) and CO₂ are amon

Question 5

Glucose is activated by ________ phosphorylation(s) by ATP during the first stage of the Embden-Meyerhof-Parnas pathway.

Accepted Answer

A)  one 
B)  two 
C)  three 
D)  four 
E)  Glucose is not phosphorylated. 
A)  one 
B)  two 
C)  three 
D)  four 
E)  Glucose is not phosphorylated.

Question 6

In their work with soil bacteria, McInerney and colleagues have found microorganisms that display metabolic pathways with net DG values as small as -20 kJ/mol. This is an example of

Accepted Answer

A)  the capacity of microorganisms to conquer a wide variety of environments. 
B)  microorganisms contradicting the laws of thermodynamics. 
C)  growth near thermodynamic equilibrium. 
D)  growth that depends on the concentration of reactants but not products. 
E)  enthalpic growth. 
A)  the capacity of microorganisms to conquer a wide variety of environments. 
B)  microorganisms contradicting the laws of thermodynamics. 
C)  growth near thermodynamic equilibrium. 
D)  growth that depends on the concentration of reactants but not products. 
E)  enthalpic growth.

Question 7

Using the table below, what is the best method for obtaining energy from catabolizing ethanol, and why?

Accepted Answer

A)  the catabolism of ethanol without an oxidant, because the DG is almost positive 
B)  the oxidation of ethanol with   as the oxidant is because of the large yield of energy released 
C)  the oxidation of ethanol with oxygen, because the DG is the largest negative number indicating the large yield of energy released. 
D)  The oxidation of ethanol yields too little biomass to be catabolized. 
E)  None-ethanol can only be catabolized syntrophically. 
A)  the catabolism of ethanol without an oxidant, because the DG is almost positive 
B)  the oxidation of ethanol with   as the oxidant is because of the large yield of energy released 
C)  the oxidation of ethanol with oxygen, because the DG is the largest negative number indicating the large yield of energy released. 
D)  The oxidation of ethanol yields too little biomass to be catabolized. 
E)  None-ethanol can only be catabolized syntrophically.

Question 8

The catabolism of glucose is central to the overall hydrolysis of polysaccharides in an environment. Compare and contrast the analogous catabolism of polyaromatic compounds found in nature.

Accepted Answer

Polyaromatic compounds found in nature i

Question 9

Which of the following is NOT correct with respect to the redox pair NAD⁺/NADH?

Accepted Answer

A)  The nicotinamide ring is a relatively stable aromatic structure. 
B)  The nicotinamide ring is a heteroaromatic because it has a noncarbon atom in position 4. 
C)  The nicotinamide ring may accept two electrons at carbon 1, becoming a nonaromatic ring. 
D)  The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD+. 
E)  NADH can accept electrons from an electron transport system. 
A)  The nicotinamide ring is a relatively stable aromatic structure. 
B)  The nicotinamide ring is a heteroaromatic because it has a noncarbon atom in position 4. 
C)  The nicotinamide ring may accept two electrons at carbon 1, becoming a nonaromatic ring. 
D)  The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD+. 
E)  NADH can accept electrons from an electron transport system.

Question 10

Describe the Entner-Doudoroff (ED) pathway. What are the advantages to microorganisms that display the ED pathway?

Accepted Answer

Glucose is oxidized to the sugar acid 6-

Question 11

Some intestinal bacteria, such as Escherichia coli, feed on ________ from mucus secretions using the Entner-Doudoroff pathway.

Accepted Answer

A)  gluconate 
B)  glucose 
C)  pyruvate 
D)  2-oxoglutarate 
E)  oxaloacetate 
A)  gluconate 
B)  glucose 
C)  pyruvate 
D)  2-oxoglutarate 
E)  oxaloacetate

Question 12

When studying an enzymatic reaction, should one consider DG, DG⁰, or DG⁰' when considering the thermodynamics of the reaction, and why?

Accepted Answer

A)  ΔDG0, because it considers standard conditions as well as biochemically relevant conditions such as the concentrations of substrates and products 
B)  ΔDG0, because it considers standard conditions 
C)  ΔDG, because it considers defined conditions such as pH 
D)  ΔDG, because it considers concentrations of reactants as products. 
E)  ΔDG0, because it considers entropy and enthalpy. 
A)  ΔDG0, because it considers standard conditions as well as biochemically relevant conditions such as the concentrations of substrates and products 
B)  ΔDG0, because it considers standard conditions 
C)  ΔDG, because it considers defined conditions such as pH 
D)  ΔDG, because it considers concentrations of reactants as products. 
E)  ΔDG0, because it considers entropy and enthalpy.

Question 13

Each of the following was used to elucidate the TCA cycle EXCEPT

Accepted Answer

A)  using radiolabeled acetate to determine which carbons were oxidized to CO₂ . 
B)  the use of crude enzyme preparations from a variety of sources such as cucumber seeds and beef liver. 
C)  adding a variety of short-chain fatty acids commonly found in cells to detect activity. 
D)  the use of C14-labeled carbon compounds as a source of carbon under anoxic conditions. 
E)  using C13 to determine which intermediates are enriched under various growth conditions. 
A)  using radiolabeled acetate to determine which carbons were oxidized to CO₂ . 
B)  the use of crude enzyme preparations from a variety of sources such as cucumber seeds and beef liver. 
C)  adding a variety of short-chain fatty acids commonly found in cells to detect activity. 
D)  the use of C14-labeled carbon compounds as a source of carbon under anoxic conditions. 
E)  using C13 to determine which intermediates are enriched under various growth conditions.

Question 14

In amphibolic pathways, enzymes do NOT

Accepted Answer

A)  function only in the biosynthetic direction. 
B)  function only in the catabolic direction. 
C)  function in both directions. 
D)  carry out reactions that are otherwise thermodynamically impossible. 
E)  have activity dependent on concentrations of reactants and products. 
A)  function only in the biosynthetic direction. 
B)  function only in the catabolic direction. 
C)  function in both directions. 
D)  carry out reactions that are otherwise thermodynamically impossible. 
E)  have activity dependent on concentrations of reactants and products.

Question 15

Hydrogen-generating reactions in Syntrophus and Syntrophomonas have DG°' > 0. Can these organisms obtain energy from hydrogen formation?

Accepted Answer

A)  No, they cannot. 
B)  No-they produce energy by breaking down molecules such as benzoate or butyrate. 
C)  Yes-hydrogen-producing microorganisms coexist in syntrophy with H₂-consuming bacteria. Utilization of H₂ (DG°' < 0) drives the process forward. 
D)  Yes, but only when oxygen is present. 
E)  Yes-this happens in sewage but never in a laboratory setting. 
A)  No, they cannot. 
B)  No-they produce energy by breaking down molecules such as benzoate or butyrate. 
C)  Yes-hydrogen-producing microorganisms coexist in syntrophy with H₂-consuming bacteria. Utilization of H₂ (DG°' < 0) drives the process forward. 
D)  Yes, but only when oxygen is present. 
E)  Yes-this happens in sewage but never in a laboratory setting.

Question 16

What technique can be used to determine entropy and enthalpy changes associated with biochemical reactions?

Accepted Answer

A)  nuclear magnetic resonance 
B)  calorimetry 
C)  electron microscopy 
D)  mass spectroscopy 
E)  measurement of light levels 
A)  nuclear magnetic resonance 
B)  calorimetry 
C)  electron microscopy 
D)  mass spectroscopy 
E)  measurement of light levels

Question 17

Some bacteria in the human gut microbiota primarily feed on glucose derivatives from mucus secretions. Which of the following is NOT correct with respect to "mucus farming" by bacteria?

Accepted Answer

A)  Bacteroides thetaiotaomicron and other bacteria induce the colon to produce mucus. 
B)  Mucus-derived sugar acids are metabolized via the Entner-Doudoroff pathway. 
C)  Sugar acids must be converted to 6-phosphogluconate in order to enter the Entner-Doudoroff pathway. 
D)  The glucose derivatives are converted to glucose and degraded via the Embden-Meyerhof-Parnas pathway. 
E)  This metabolism has been studied via genomics and genetic studies. 
A)  Bacteroides thetaiotaomicron and other bacteria induce the colon to produce mucus. 
B)  Mucus-derived sugar acids are metabolized via the Entner-Doudoroff pathway. 
C)  Sugar acids must be converted to 6-phosphogluconate in order to enter the Entner-Doudoroff pathway. 
D)  The glucose derivatives are converted to glucose and degraded via the Embden-Meyerhof-Parnas pathway. 
E)  This metabolism has been studied via genomics and genetic studies.

Question 18

Clostridium acetobutylicum has been used to produce which solvents?

Accepted Answer

A)  acetate and butyrate 
B)  acetone and butanol 
C)  methanol and ethanol 
D)  formate and ethanol 
E)  propanol and mixed acids 
A)  acetate and butyrate 
B)  acetone and butanol 
C)  methanol and ethanol 
D)  formate and ethanol 
E)  propanol and mixed acids

Question 19

Species of Pseudomonas and Rhodococcus can degrade benzoate and other aromatic molecules, either aerobically or anaerobically. Which of the following is NOT correct regarding anaerobic degradation of aromatic molecules?

Accepted Answer

A)  It takes longer than aerobic degradation. 
B)  It is critical because bacterial anaerobic habitats are more abundant than aerobic ones. 
C)  Benzoate is activated to benzoyl-CoA prior to its degradation. 
D)  It proceeds via production of catechols. 
E)  The high initial investment of energy comes from either anaerobic phototrophy or anaerobic respiration. 
A)  It takes longer than aerobic degradation. 
B)  It is critical because bacterial anaerobic habitats are more abundant than aerobic ones. 
C)  Benzoate is activated to benzoyl-CoA prior to its degradation. 
D)  It proceeds via production of catechols. 
E)  The high initial investment of energy comes from either anaerobic phototrophy or anaerobic respiration.

Question 20

Define the human metagenome. Describe an example to demonstrate the importance of the metagenome.

Accepted Answer

The human metagenome is composed of the

Exam 13: Energetics and Catabolism

All of the following are reasons to oxidize glucose in a series of steps EXCEPT to

The base adenine forms from ________ in experiments simulating the origin of life on Earth.

Bacteria synthesize ribose for nucleotides using which pathway?

Escherichia coli degrades human waste in the colon using mixed-acid fermentation. Why is this a factor of concern in some medical procedures, such as colonoscopy?

Glucose is activated by ________ phosphorylation(s) by ATP during the first stage of the Embden-Meyerhof-Parnas pathway.

In their work with soil bacteria, McInerney and colleagues have found microorganisms that display metabolic pathways with net DG values as small as -20 kJ/mol. This is an example of

Using the table below, what is the best method for obtaining energy from catabolizing ethanol, and why?

The catabolism of glucose is central to the overall hydrolysis of polysaccharides in an environment. Compare and contrast the analogous catabolism of polyaromatic compounds found in nature.

Which of the following is NOT correct with respect to the redox pair NAD⁺/NADH?

Describe the Entner-Doudoroff (ED) pathway. What are the advantages to microorganisms that display the ED pathway?

Some intestinal bacteria, such as Escherichia coli, feed on ________ from mucus secretions using the Entner-Doudoroff pathway.

When studying an enzymatic reaction, should one consider DG, DG⁰, or DG⁰' when considering the thermodynamics of the reaction, and why?

Each of the following was used to elucidate the TCA cycle EXCEPT

In amphibolic pathways, enzymes do NOT

Hydrogen-generating reactions in Syntrophus and Syntrophomonas have DG°' > 0. Can these organisms obtain energy from hydrogen formation?

What technique can be used to determine entropy and enthalpy changes associated with biochemical reactions?

Some bacteria in the human gut microbiota primarily feed on glucose derivatives from mucus secretions. Which of the following is NOT correct with respect to "mucus farming" by bacteria?

Clostridium acetobutylicum has been used to produce which solvents?

Species of Pseudomonas and Rhodococcus can degrade benzoate and other aromatic molecules, either aerobically or anaerobically. Which of the following is NOT correct regarding anaerobic degradation of aromatic molecules?

Define the human metagenome. Describe an example to demonstrate the importance of the metagenome.

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

Filters