Deck 7: Microbial Metabolism

Question 1

Feedback inhibition,a negative feedback mechanism that regulates enzymes,is best described as

A)substrate binding to DNA,blocking enzyme transcription.
B)product binding to DNA,blocking enzyme transcription.
C)substrate binding to enzyme in noncompetitive site.
D)product binding to enzyme in noncompetitive site.
E)None of the choices is correct.

Answer 1

D

Question 2

A holoenzyme is a combination of a protein and one or more substances called

A)substrates.
B)apoenzymes.
C)catalysts.
D)cofactors.
E)None of the choices is correct.

Answer 2

D

Question 3

During aerobic cellular respiration,the final electron acceptor is

A)pyruvic acid.
B)oxygen.
C)nitrate.
D)cytochrome c.
E)FAD.

Answer 3

B

Question 4

When the product of reaction A becomes the reactant of reaction B,the metabolic pathway is

A)linear.
B)bidirectional.
C)convergent.
D)cyclic.
E)divergent.

Question 5

Each of the following is true of enzymes except

A)they can be used over and over.
B)they may or may not require cofactors.
C)their active site is specific to the substrate.
D)they increase the initial energy required for a reaction to start.
E)All of the choices are true of enzymes.

Question 6

Enzymes are

A)broken down in reactions that require energy input.
B)proteins that function as catalysts.
C)used up in chemical reactions.
D)not needed for catabolic reactions.
E)All of the choices are correct.

Question 7

An apoenzyme is

A)part of a simple enzyme.
B)also called a coenzyme.
C)the protein part of a holoenzyme.
D)often an inorganic metal ion.
E)an RNA molecule.

Question 8

The cell's metabolic reactions involve the participation of _____ that lower the activation energy needed for the initiation of a reaction.

A)cofactors
B)vitamins
C)enzymes
D)ATP
E)coenzymes

Question 9

Each of the following are denaturing agents except

A)high temperature.
B)low temperature.
C)high pH.
D)low pH.
E)All of the choices are correct.

Question 10

The breakdown of peptidoglycan to N-acetylmuramic acid,N-acetylglucosamine,and peptides is an example of

A)anabolism.
B)catabolism.
C)phosphorylation.
D)fermentation.
E)synthesis.

Question 11

Enzymes that hydrolyze a peptide bond are called

A)phosphotransferases.
B)oxidoreductases.
C)peptidases.
D)aminotransferases.
E)ligases.

Question 12

Important components of coenzymes are

A)vitamins.
B)metallic ions.
C)active sites.
D)substrates.
E)ribozymes.

Question 13

Reactants are converted to products by

A)enzymes releasing energy.
B)breaking and forming bonds.
C)enzymes binding to reactants.
D)reactants releasing energy.
E)None of the choices is correct.

Question 14

When enzyme action stops due to a buildup of end product,this control is called

A)feedback inhibition (negative feedback).
B)competitive inhibition.
C)enzyme induction.
D)enzyme repression.
E)None of the choices is correct.

Question 15

Enzymes that are always present,regardless of the amount of substrate,are

A)apoenzymes.
B)axoenzymes.
C)constitutive enzymes.
D)regulated enzymes.
E)endoenzymes.

Question 16

Formation of peptide bonds between amino acids to build a polypeptide would be called

A)anabolism.
B)phosphorylation.
C)fermentation.
D)exergonic.
E)glycolysis.

Question 17

All of the chemical reactions of the cell are called

A)catabolism.
B)redox reactions.
C)phosphorylation.
D)metabolism.
E)cellular respiration.

Question 18

Most electron carriers are

A)coenzymes.
B)enzymes.
C)hydrogens.
D)inorganic phosphates.
E)All of the choices are correct.

Question 19

Enzymes that are only produced when substrate is present are termed

A)exoenzymes.
B)endoenzymes.
C)constitutive enzymes.
D)induced enzymes.
E)conjugated enzymes.

Question 20

Metabolic pathways that regenerate their starting point are called _____ pathways.

A)linear
B)bidirectional
C)convergent
D)cyclic
E)divergent

Question 21

The formation of citrate from oxaloacetate and an acetyl-CoA begins

A)glycolysis.
B)the electron transport system.
C)the Krebs cycle.
D)fermentation.
E)oxidative phosphorylation.

Question 22

The redox carriers of the electron transport chain that have a tightly bound metal atom responsible for accepting and donating electrons are

A)NAD.
B)FAD.
C)NADP.
D)the cytochromes.
E)the flavoproteins.

Question 23

Exergonic reactions

A)include synthesis of large carbohydrates.
B)only occur in heterotrophs.
C)release energy.
D)do not occur in anaerobic cellular respiration.
E)occur when ADP binds to inorganic phosphate to form ATP.

Question 24

As the electron transport carriers shuttle electrons,they actively pump _____ into the outer membrane compartment setting up a concentration gradient called the proton motive force.

A)ATP
B)phosphate
C)hydrogen ions
D)oxygen
E)NADH

Question 25

During which of the phases of cellular respiration is the majority of ATP formed?

A)electron transport
B)Krebs cycle
C)glycolysis
D)processing of pyruvic acid for the Krebs cycle
E)All phases produce the same number of ATP molecules.

Question 26

Glycolysis

A)uses 2 ATPs,produces 2 ATPs,and requires oxygen.
B)uses 2 ATPs,produces 4 ATPs,and requires oxygen.
C)uses 2 ATPs,produces 4 ATPs,without using oxygen.
D)uses 2 ATPs,produces 2 ATPs,without using oxygen.
E)None of the choices is correct.

Question 27

In bacterial cells,the electron transport system is located in the

A)cell membrane.
B)mitochondria.
C)chloroplasts.
D)ribosomes.
E)cytoplasm.

Question 28

All of the following pertain to glycolysis except it

A)occurs without oxygen.
B)ends with formation of pyruvic acid.
C)occurs during fermentation.
D)degrades glucose to CO₂ and H₂O.
E)involves reduction of NAD.

Question 29

NADH and FADH₂ molecules are oxidized in which step of the aerobic respiration process?

A)electron transport system
B)Krebs cycle
C)glycolysis
D)step before Krebs cycle

Question 30

The majority of reduced NAD is produced in

A)glycolysis.
B)the Krebs cycle.
C)the electron transport chain.
D)photosynthesis.
E)None of the choices is correct.

Question 31

FAD,NAD,and coenzyme A are all _____ carriers.

A)hydrogen
B)electron
C)ATP
D)hydrogen and electron
E)None of the choices is correct.

Question 32

Each NADH that enters the electron transport system gives rise to a maximum of _____ ATP.

A)2
B)3
C)24
D)36
E)38

Question 33

Reduction of nitrogen-oxygen ions,such as nitrate,by some bacteria is called

A)aerobic respiration.
B)denitrification.
C)nitrification.
D)fermentation.
E)deamination.

Question 34

In the cell,energy released by electrons is often used to phosphorylate

A)ATP.
B)ADP.
C)pyruvic acid.
D)oxygen.
E)NAD.

Question 35

In bacterial cells,when glucose is completely oxidized by all the pathways of aerobic cellular respiration,what is the maximum number of ATP generated?

A)2 ATP
B)3 ATP
C)24 ATP
D)42 ATP
E)38 ATP

Question 36

Each FADH₂ from the Krebs cycle enters the electron transport system and gives rise to a maximum of _____ ATP(s).

A)1
B)2
C)3
D)4
E)5

Question 37

Which of the following is not true of anaerobic respiration?

A)involves glycolysis
B)generates some ATP
C)utilizes an electron transport system
D)uses the same final electron acceptors as aerobic respiration

Question 38

In addition to electrons,which of the following is also involved in electron transfer?

A)ADP
B)glucose
C)carbon
D)hydrogen
E)carbon dioxide

Question 39

How many carbon dioxide molecules are produced by the complete aerobic breakdown of one glucose molecule?

A)2
B)3
C)4
D)5
E)6

Question 40

Which of the following is not involved in the step that occurs between glycolysis and the Krebs cycle?

A)one NADH is formed
B)one carbon dioxide is released
C)coenzyme A attaches to an acetyl group
D)pyruvic acid accepts electrons from NADH

Question 41

Deamination is the removal of a(n)_____ group in proteins.

A)carboxyl
B)amino
C)phosphate
D)hydroxyl
E)None of the choices is correct.

Question 42

Denaturing an apoenzyme will destroy the three-dimensional shape of the protein,making it nonfunctional.

Question 43

You are knowledgeable about cellular metabolism.Which of the following processes is common to fermentation,anaerobic respiration,and aerobic respiration?

A)glycolysis
B)the Krebs cycle
C)the electron transport system
D)glycosylation

Question 44

You instruct the patient that although bacterial cells can also undergo aerobic respiration,

A)they make less ATP in this process than eukaryotic cells.
B)the Krebs cycle takes place in the mitochondrion in these cells.
C)glycolysis takes place in the mitochondrion in these cells.
D)the electron transport chain is present in the plasma membrane of these cells.

Question 45

All aerobic bacterial species have identical electron acceptors in their electron transport systems.

Question 46

As the RN,you initiate IV fluid therapy for the patient.Knowing the importance of cellular energy production,which of the following maintenance IV fluids would you expect to be ordered by the physician?

A)0.9% sodium chloride
B)lactated ringers
C)0.45% sodium chloride
D)0.9% sodium chloride with dextrose

Question 47

Fermentation

A)requires an organic electron acceptor.
B)requires oxygen.
C)only occurs in aerobic organisms.
D)can be equivalent to aerobic respiration in ATP production.
E)None of the choices is correct.

Question 48

ATP is composed of deoxyribose,adenine,and three phosphate groups.

Question 49

ATP molecules are catalysts that lower the activation energy needed to initiate a reaction.

Question 50

The principal sites of amphibolic interaction occur during

A)glycolysis and photosynthesis.
B)the Krebs cycle and electron transport system.
C)glycolysis and the Krebs cycle.
D)fermentation and the Krebs cycle.
E)fermentation and glycolysis.

Question 51

Oxygen-containing ions are used by some bacteria as final electron acceptors.

Question 52

The property of organisms to integrate catabolic and anabolic pathways to improve cell efficiency is called

A)metabolism.
B)amphibolism.
C)anabolism.
D)catabolism.
E)biosynthesis.

Question 53

Building block molecules for biosynthetic pathways come from the cell's catabolic pathways and from the environment.

Question 54

The fermentation process always produces alcohol as at least one of its products.

Question 55

Fatty acids can be converted to acetyl-CoA for entering the Krebs cycle by the process of

A)amination.
B)deamination.
C)phosphorylation.
D)beta oxidation.
E)gluconeogenesis.

Question 56

As the RN,you are familiar with ATP production in bacterial and eukaryotic cells.How many ATP do you expect aerobic respiration to yield in the patient's cells?

A)2 ATP
B)38 ATP
C)36 ATPs
D)ATP yield is unpredictable.

Question 57

The reactions of fermentation function to produce _____ molecules for use in glycolysis.

A)pyruvic acid
B)ATP
C)NAD+
D)NADH
E)glucose

Question 58

Microbes can utilize only carbohydrates for energy production.

Question 59

When glucose is broken down by glycolysis during bacterial fermentation,how many ATP are generated?

A)2 ATP
B)3 ATP
C)24 ATP
D)36 ATP
E)38 ATP

Question 60

ATP synthase is a complex enzyme needed for oxidative phosphorylation.

Question 61

The organism sample is further tested and found to grow in the absence of oxygen.Which of three main pathways of catabolism may this organism utilize to produce energy in the absence of free oxygen?

A)aerobic respiration and fermentation
B)anaerobic respiration and aerobic respiration
C)fermentation and anaerobic respiration
D)aerobic respiration,anaerobic respiration,and fermentation

Question 62

Which of the following statements,by the patient's mother,best represents an understanding of metabolism?

A)"Metabolism involves the production of enzymes."
B)"Metabolism involves all chemical reactions and physical workings of the cell."
C)"Metabolism involves the consumption of energy for workings of the cell."
D)"Metabolism involves the production of energy for workings of the cell."

Question 63

All of the following are true of enzymes except

A)enzymes increase the rate of a chemical reaction.
B)enzymes are not part of the products of a chemical reaction.
C)enzymes create a chemical reaction.
D)enzymes are not consumed in a chemical reaction.

Question 64

The organism is found to grow throughout the entire tube of broth media.Which of the following terms best describes the oxygen requirement of this organism?

A)obligate aerobe
B)microaerophile
C)facultative anaerobe
D)obligate anaerobe

Question 65

Inborn errors of metabolism

A)are caused by infectious agents.
B)produce very specific signs and symptoms,making them easy to diagnose.
C)cannot be diagnosed by DNA testing.
D)may not become evident until adulthood.

Question 66

Please read the clinical scenario, and then answer the question that follow to become familiar with the traditional NCLEX question format.
A 67-year-old patient with severe sepsis undergoes a full infectious workup upon admittance to the intensive care unit. Cultures of urine, blood, sputum, and cerebral spinal fluid are obtained. The cultures do not yield a specific organism, so further analysis of the sample is done to determine the characteristics of the microorganism. The metabolic processes are analyzed in the lab.

-What is the maximum net yield of ATP from anaerobic respiration?

A)2 ATP
B)2-36 ATP
C)36-38 ATP
D)38-40 ATP

Question 67

Biochemical testing reveals that the organism further reduces nitrite to produce nitrous oxide.Based upon this by-product,which of the following is the most likely catabolic pathway utilized by this organism?

A)aerobic respiration
B)anaerobic respiration
C)fermentation
D)Aerobic and anaerobic respiration,as well as fermentation,can all lead to the production of nitrous oxide

Question 68

Based upon knowledge of enzymes and metabolic processes,which of the following outcomes would you educate the parents to expect if the deficiency is not treated?

A)no effect on the patient's health
B)reduced immunity in adulthood in the patient
C)mildly impaired vision in the patient
D)permanent damage to organ systems and/or death of the patient