Deck 8: Microbial Metabolism: the Chemical Crossroads of Life

Question 1

Enzymes that are only produced when substrate is present are termed ______.

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

Answer 1

induced enzymes

Question 2

The term used to describe all of the chemical reactions within a cell is ______.

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

Answer 2

metabolism

Question 3

Each of the following are 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 speci?c to the substrate
D) they increase the activation energy of a reaction
E) their action may involve minerals

Answer 3

they increase the activation energy of a reaction

Question 4

The bacterial genus Bacillus can utilize starch as a nutrient by splitting the starch molecule into smaller molecules of glucose with the addition of water. The enzymes to do this would be classi?ed as ______.

A) transferases
B) oxidoreductases
C) ligases
D) hydrolases
E) isomerases

Question 5

Important components of coenzymes are _______.

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

Question 6

Your bacterium is growing on a type of medium called casein agar, which contains milk protein (casein). There is a clear zone around the growth area of the bacterium, showing that it is synthesizing the enzymes needed to catalyze the breakdown of casein. These enzymes are considered ______.

A) apoenzymes
B) exoenzymes
C) ribozymes
D) endoenzymes

Question 7

During aerobic cellular respiration, the ?nal electron acceptor is ______.

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

Question 8

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) carbohydrate or protein in composition

Question 9

The most likely place where an exoenzyme participates in a chemical reaction is ______.

A) in mitochondria
B) within the cell membrane
C) in lysosomes
D) in cytoplasm
E) outside of the cell

Question 10

Enzymes that catalyze the removal of electrons from one substrate and the addition of electrons to another are called ______.

A) transferases
B) oxidoreductases
C) lyases
D) isomerases
E) ligases

Question 11

Enzymes that catalyze the removal of a a functional group and its subsequent attachment to a new substrate are called ______.

A) transferases
B) oxidoreductases
C) isomerases
D) lyases
E) ligases

Question 12

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 13

Reactants are converted to products by _______.

A) enzymes releasing energy
B) breaking and forming bonds
C) enzymes binding to products
D) reactants always releasing energy

Question 14

The formation of peptide bonds between amino acids to build a polypeptide is an example of ______.

A) anabolism
B) phosphorylation
C) fermentation
D) catabolism
E) glycolysis

Question 15

Anabolic reactions that involve ligases and release water molecules when bonds are formed are called ______ reactions.

A) reduction
B) condensation
C) oxidation
D) transfer

Question 16

A type of cofactor would be ______.

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

Question 17

Ribozymes are ______.

A) ribosomes which catalyze reactions
B) unique to prokaryotes
C) unique to eukaryotes
D) catalysts for RNA splicing
E) catalysts for DNA splicing

Question 18

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

A) substrates
B) apoenzymes
C) catalysts
D) cofactors
E) ribozymes

Question 19

All of the following are exoenzymes except ______.

A) ATP synthase
B) streptokinase
C) penicillinase
D) collagenase

Question 20

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 21

Substrate-level phosphorylation occurs in _______.

A) glycolysis and the electron transport chain
B) photosynthesis and glycolysis
C) glycolysis and the Krebs cycle
D) the Krebs cycle and the electron transport system
E) the electron transport system only

Question 22

Exergonic reactions _______.

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

Question 23

All of the following pertain to glycolysis except _______.

A) it occurs without oxygen
B) it ends with formation of pyruvic acid
C) it occurs during fermentation
D) it degrades glucose to CO? and H?O
E) it involves reduction of NAD

Question 24

Noncompetitive inhibition is best described as _______.

A) the substrate binding to DNA, blocking enzyme transcription
B) the end product binding to DNA, blocking enzyme transcription
C) the substrate binding to enzyme in a regulatory site
D) the end product binding to enzyme in noncompetitive site
E) an anabolic reaction

Question 25

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

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

Question 26

Most electron carriers are ______.

A) coenzymes
B) enzymes
C) hydrogen
D) inorganic phosphate

Question 27

Glycolysis uses 2 ATP and produces _______.

A) 2 ATP only if oxygen is present
B) 2 ATP without oxygen
C) 4 ATP only if oxygen is present
D) 4 ATP without oxygen

Question 28

When the product of reaction A becomes the reactant of reaction B, this exempli?es a _______ metabolic pathway.

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

Question 29

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

A) apoenzymes
B) exoenzymes
C) constitutive enzymes
D) regulated enzymes
E) endoenzymes

Question 30

Each of the following are denaturing agents except ______.

A) high temperature
B) low temperature
C) high pH
D) low pH

Question 31

The formation of citric acid from oxaloacetic acid and an acetyl group begins ______.

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

Question 32

When enzyme action stops due to a buildup of end product that acts as a regulatory molecule, this control is called ______.

A) competitive inhibition
B) enzyme induction
C) enzyme repression
D) noncompetitive inhibition

Question 33

Enzymes that function inside a cell are ______.

A) apoenzymes
B) exoenzymes
C) constitutive enzymes
D) regulated enzymes
E) endoenzymes

Question 34

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

A) Reduction of NAD+
B) Coenzyme A attaches to an acetyl group
C) Oxidation of pyruvic acid
D) Pyruvic acid accepts electrons from NADH

Question 35

Which of the following is not a process that regenerates ATP?

A) Oxidative phosphorylation
B) Reductive phosphorylation
C) Substrate-level phosphorylation
D) Photophosphorylation

Question 36

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 37

The step involving ATP, hexokinase, and the phosphorylation of glucose to glucose-6-phosphate is _______.

A) the ?nal step of the Krebs cycle
B) the ?rst redox reaction of the electron transport system
C) an example of oxidative phosphorylation
D) an example of substrate-level phosphorylation
E) an example of photophosphorylation

Question 38

Each of the following are electron carriers except ______.

A) NAD
B) FAD
C) NADP
D) FADP

Question 39

FAD, NADP, NAD, and coenzyme A are all carriers of ________.

A) hydrogens
B) electrons
C) ATP
D) Both hydrogens and electrons are correct.

Question 40

Metabolic pathways that regenerate their starting molecule are called ______ pathways.

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

Question 41

Each NADH that enters the electron transport system results in the production of _____ ATPs.

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

Question 42

Reduction of nitrogen-oxygen ions and compounds by some bacteria is called ______.

A) aerobic respiration
B) denitri?cation
C) nitri?cation
D) fermentation
E) deamination

Question 43

Which of the following is not true of anaerobic respiration?

A) It involves glycolysis.
B) It generates some ATP.
C) It utilizes an electron transport system.
D) It uses the same ?nal electron acceptor as aerobic respiration.

Question 44

Which of the following is not a photosynthetic pigment?

A) Carotenoid
B) Leukophyll
C) Phycobilin
D) Chlorophyll

Question 45

In which stage of aerobic respiration is water produced?

A) Glycolysis
B) The Krebs cycle
C) The electron transport system

Question 46

Fermentation ______.

A) requires an organic electron acceptor
B) requires oxygen
C) only occurs in aerobic organisms
D) is equivalent to aerobic respiration in ATP production
E) is the same as anaerobic respiration

Question 47

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 48

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

A) Electron transport system
B) The Krebs cycle
C) Glycolysis
D) Processing of pyruvic acid for the Krebs cycle
E) All phases produce the same number of ATP molecules.

Question 49

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 50

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

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

Question 51

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

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

Question 52

When glucose is broken down by glycolysis during bacterial fermentation, what is the usual net production of ATP?

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

Question 53

In which pathway is the most NADH generated?

A) The electron transport system
B) The Krebs cycle
C) Glycolysis
D) Alcoholic fermentation
E) Mixed acid fermentation

Question 54

Mixed acid fermentation _______.

A) produces butyric acid
B) occurs in all bacteria
C) produces several different acids plus CO? and H2 gases
D) is seen in Streptococcus and Lactobacillus
E) also produces ethanol

Question 55

An oxidase detection test can be used to identify certain bacteria because they are missing or lack expression of ______.

A) cytochrome C oxidase
B) NAD
C) mitochondria
D) ATP synthase
E) coenzyme Q

Question 56

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

Question 57

Each FADH2 from the Krebs cycle that enters the electron transport system results in the production of _____ ATP(s).

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

Question 58

What chemical causes death in many eukaryotes because it blocks cytochrome C oxidase?

A) Copper
B) Iron
C) Cyanide
D) Oxygen
E) Carbon monoxide

Question 59

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

A) NAD molecules
B) FAD molecules
C) NADP molecules
D) the cytochromes
E) the ?avoproteins

Question 60

The majority of NADH is produced in ______.

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

Question 61

Which of the following characterize the Calvin cycle?

A) A process that requires light
B) Nitrogen is ?xed into an organic form
C) Produces glucose as an end product
D) Produces carbon dioxide and water
E) Produces oxygen

Question 62

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

Question 63

Hydrolysis reactions are catabolic reactions that use water to split the reactant into smaller subunits.

Question 64

Which of the following is not true of the light-dependent reactions of photosynthesis?

A) They occur in thylakoid membranes.
B) They generate NADPH.
C) They generate glucose from CO? and H?O.
D) The photons cause magnesium to release electrons.
E) ATP is generated by a chemiosmotic mechanism.

Question 65

The best way to control a metabolic pathway is to control the fastest enzyme in the series.

Question 66

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

Question 67

Oxygen-containing ions are used by some bacteria in their electron transport system.

Question 68

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

Question 69

Only yeast produce alcohol as a fermentation product.

Question 70

Microbes can utilize only carbohydrates for energy production.

Question 71

The property of organisms to integrate catabolic and anabolic pathways to improve cell e?ciency is called ______.

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

Question 72

Intermediates from the Krebs cycle can be converted to amino acids by the process of ______.

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

Question 73

ATP synthase is a complex enzyme needed for oxidative phosphorylation.

Question 74

The unknown bacterium that you are testing makes the enzyme phenyalanine deaminase, as indicated by the results of a phenylalanine test. This enzyme facilitates the removal of a/an ______ group from the organic compound so it can be converted into an intermediate compound for the krebs cycle.

A) carboxyl
B) amino
C) phosphate
D) hydroxyl

Question 75

Exoenzymes from pathogens are called virulence factors.

Question 76

Glyceraldehyde-3-phosphate is an intermediary of glycolysis that can also be utilized in biosynthetic pathways.

Question 77

The principle sites of amphibolic interaction occur during ______.

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

Question 78

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

Question 79

The process of forming glucose from various metabolic intermediates is called ______.

A) glycolysis
B) amphibolism
C) phosphorylation
D) amination
E) gluconeogenesis

Question 80

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