Exam #2

Question 1

Which of the following diseases is (are) caused by prions?

Scrapie

Mad cow disease

Kuru and Creutzfeldt-Jakob Disease

All of the choices are correct.

Answer 1

all of the choices are correct

Question 2

Prions consist of proteins and have no apparent nucleic acid genome T o F

Answer 2

True

Question 3

Most bacterial and archaeal cells divide by _________

Answer 3

Binary Fission

Question 4

Which of the following is the correct order for binary fission?

A septum forms at the midcell, the cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell.

The cell elongates, a septum forms at midcell, the cell replicates its chromosome, and separates the chromosome into the two parts of the cell.

The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell.

None of the choices are correct.

Answer 4

The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell.

Question 5

The ________ is a group of proteins needed for DNA synthesis that assembles at the origin of replication.

Answer 5

replisome

Question 6

The process of forming a cross wall between two daughter cells is known as _________.

Answer 6

Septation

Question 7

The site at which replication of DNA starts in bacterial cells is known as the

Answer 7

origin of replication

Question 8

During cytokinesis, a critical step in septation is the assembly of the

Answer 8

z ring

Question 9

Organisms that grow well at 0°C and have optimum growth temperatures of 15°C or lower are called?

Answer 9

psychrophiles

Question 10

Organisms that do not require oxygen for growth but grow better in its presence are called

Answer 10

facultative anaerobes

Question 11

Organisms that ignore oxygen and grow equally well in its presence or absence are called _________

Answer 11

aerotolerant

Question 12

Organisms that are damaged by the normal atmospheric levels of oxygen (20%) but require oxygen at levels of 2–10% for growth are called

Answer 12

microaerophiles

Question 13

Organisms that require increased pressure for optimum growth are called

Answer 13

barophilic

Question 14

Most known microorganisms maintain their internal pH

Answer 14

near neutral (pH 7)

Question 15

Membranes of some thermophilic Archaea are stabilized by ether-linked phospholipids. T o F

Answer 15

True

Question 16

Membranes of thermophilic bacteria are stabilized by phospholipids with

Answer 16

fatty acids that tend to be more saturated

Question 17

What is Quorum sensing?

Answer 17

is a phenomenon in which bacteria monitor their own population density

depends on the sensing of signal protein molecules

plays an important role in formation of biofilms by Pseudomonas aeruginosa

Question 18

What are the four step of Quorum Sensing

Answer 18

1. Surface (substratum) is preconditioned by environmental molecules.
2. Microbes attach and detach from the preconditioned surface
3. Microbes attach and detach from the preconditioned surface
4. Biofilm matures and some microorganisms escape to the planktonic state.

Question 19

Which of the following is a reason(s) for the decline in cell numbers during the death phase?

Depletion of nutrients

Accumulation of toxic waste materials

Depletion of O2

All of the choices are correct.

Answer 19

all of them are correct

Question 20

A growth medium that favors the growth of some microorganisms but inhibits the growth of other microorganisms is
neither selective nor differential

both selective and differential

a differential medium

a selective medium

Answer 20

selective medium

Question 21

A growth medium that distinguishes among different groups of bacteria on the basis of their biological characteristics is called a(n)

Answer 21

differential medium

Question 22

When antiseptics and disinfectants are compared, antiseptics are generally _________.

less toxic

more toxic

equally as toxic

unpredictable in toxicity

Answer 22

less toxic

Question 23

The destruction or removal of all viable organisms is called

Answer 23

Sterilization

Question 24

The reduction of the microbial population to levels that are considered safe by public health standards is called

Answer 24

sanitization

Question 25

Ultraviolet radiation is an effective means of sterilizing surfaces T o F

Answer 25

true

Question 26

Dry heat methods usually require lower temperatures and shorter exposure times than moist heat methods to achieve the same degree of killing because of the drying effects of this form of heat. T o F

Answer 26

False

Question 27

If one left a "pasteurized" flask of broth for a long time at room temperature, it would stay sterile forever, at least in principle. T o F

Answer 27

False

Question 28

Which of the following is MOST effective against resistant endospores? Multiple Choice Autoclaving Boiling Pasteurization All of these are equally effective against resistant endospores.

Answer 28

Autoclaving

Question 29

Moist heat sterilizes by _________. causing the formation of thymine dimers denaturing proteins causing the production of singlet oxygen All of the choices are correct.

Answer 29

Denaturing proteins

Question 30

The two most important alcohol germicides are _________ and _________

Answer 30

ethanol; isopropanol

Question 31

Alcohols are widely used as antiseptics and disinfectants because they are effective against endospores as well as vegetative cells T o F

Answer 31

False

Question 32

A drug that disrupts a microbial function not found in animal cells usually has a higher therapeutic index T o F

Answer 32

true

Question 33

The ratio of toxic dose to therapeutic dose is called the

Answer 33

therapeutic index

Question 34

The minimal lethal concentration (MLC) is the lowest concentration of a drug that prevents growth of a particular pathogen highest concentration of a drug that prevents growth of a particular pathogen lowest concentration of a drug that kills a particular pathogen highest concentration of a drug that kills a particular pathogen

Answer 34

lowest concentration of a drug that kills a particular pathogen

Question 35

The lowest concentration of an antibiotic that prevents growth is the _________. minimal inhibitory concentration (MIC) minimal lethal concentration (MLC) 50% inhibitory dose All of the choices are correct.

Answer 35

minimal inhibitory concentration (MIC)

Question 36

Aminoglycoside antibiotics _________. inhibit cell wall synthesis inhibit folic acid biosynthesis bind to the 30S ribosomal subunit bind to bacterial DNA polymerase

Answer 36

bind to the 30S ribosomal subunit

Question 37

Which of the following is a useful mechanism of action for an antibacterial drug? Inhibition of cell wall synthesis Inhibition of protein synthesis Interference with RNA and DNA synthesis All of the choices are correct.

Answer 37

all of these

Question 38

Protein synthesis inhibitors have a low therapeutic index because they usually cannot discriminate between prokaryotic and eukaryotic ribosomes. T o F

Answer 38

False

Question 39

The antiviral drugs currently approved for use in HIV disease include _________ nucleoside reverse transcriptase inhibitors nonnucleoside reverse transcriptase inhibitors protease inhibitors fusion inhibitors All of the choices are correct.

Answer 39

all are correct

Question 40

treatment of fungal infections is more difficult than treatment of bacterial infections because the greater metabolic similarity between the fungi and their hosts limits the ability of a drug to have a selective toxicity T O F

Answer 40

True

Question 41

Which of the following is (are) used by microorganisms to become resistant to a particular drug? Enzymatic inactivation of the drug Exclusion of the drug from the cell An alternate metabolic pathway that bypasses the drug-sensitive step All of the choices are correct.

Answer 41

all of the choices are correct

Question 42

A chemical reaction that requires an input of energy in order to proceed is

Answer 42

Endergonic

Question 43

he change in _________is the amount of energy in a system that is available to do work

Answer 43

Free energy

Question 44

The standard reduction potential of a redox reaction is a measure of the tendency of the _________ to _________ electrons. reductant; gain reductant; lose oxidant; gain oxidant; lose

Answer 44

reductant; lose

Question 45

he energy required to bring the substrates of a reaction together in the correct way to reach the transition state is called

Answer 45

Activation energy

Question 46

Enzyme activity can be controlled by _________. allosteric regulation covalent modification feedback (end product) inhibition All of the choices are correct.

Answer 46

all are correct

Question 47

The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhof pathway in PROKARYOTES is _________. Multiple Choice 2 36 38 85

Answer 47

2

Question 48

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

Answer 48

true

Question 49

The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is

Answer 49

32

Question 50

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 are correct.

Answer 50

all of them are correct

Question 51

A newly described bacterial species has been shown to use CO2 as its carbon source. Its energy source and its source of reducing power (electrons) are inorganic chemicals. Which term would best describe this nutritional type? Chemolithoheterotroph Photoorganoheterotroph Photolithoheterotroph Chemolithoautotroph

Answer 51

Chemolithoautotroph

Question 52

Which of the following is the major glycolytic pathway used by plants and animals? Multiple Choice Tricarboxylic acid cycle Embden-Meyerhof pathway Entner-Doudoroff pathway Pentose phosphate pathway

Answer 52

Embden-Meyerhof pathway

Question 53

How is ATP produced during fermentation? Cyclic phosphorylation Substrate-level phosphorylation Oxidative phosphorylation Use of proton motive force to drive ATP synthase Chemosynthetic phosphorylation

Answer 53

Substrate-level phosphorylation

Question 54

What enzymes hydrolyze proteins, releasing amino acids? Tranaminases Proteases Decarboxylases Deaminases

Answer 54

Proteases

Question 55

The energy source for substrate-level phosphorylation (SLP) differs from that of oxidative phosphorylation (OP) in that _________. SLP is driven using energy provided by a proton motive force, whereas the energy to remove a phosphate group from ATP during OP comes from the direct transfer of a phosphate group from a molecule with a lower phosphate transfer potential than ATP OP is driven using energy provided by a proton motive force, whereas the energy to add a phosphate group to ADP during SLP comes from the direct transfer of a phosphate group from a molecule with a lower phosphate transfer potential than ATP OP is driven using energy provided by a proton motive force, whereas the energy to add a phosphate group to ADP during SLP comes from the direct transfer of a phosphate group from a molecule with a higher phosphate transfer potential than ATP SLP is driven using energy provided by a proton motive force, whereas the energy to add a phosphate group to ADP during OP comes from the direct transfer of a phosphate group from a molecule with a higher phosphate transfer potential than ATP

Answer 55

OP is driven using energy provided by a proton motive force, whereas the energy to add a phosphate group to ADP during SLP comes from the direct transfer of a phosphate group from a molecule with a higher phosphate transfer potential than ATPCorrect

Question 56

Chemolithotrophs obtain their energy from _________. inorganic molecules that directly transfer a phosphate group to ATP during substrate-level phosphorylation inorganic molecules that are oxidized, providing electrons to create a proton motive force that drives oxidative phosphorylation organic molecules that are oxidized via a glycolytic pathway and the TCA cycle inorganic molecules that are reduced, providing electrons to create a proton motive force that drives oxidative phosphorylation

Answer 56

inorganic molecules that are oxidized, providing electrons to create a proton motive force that drives oxidative phosphorylation

Question 57

Which of the following has the phases of the Calvin-Benson cycle in the correct order, starting with the entry of ribulose 1,5-bisphosphate? Reduction phase, carboxylation phase, regeneration phase Carboxylation phase, reduction phase, regeneration phase Carboxylation phase, regeneration phase, reduction phase Regeneration phase, carboxylation phase, reduction phas

Answer 57

Carboxylation phase, reduction phase, regeneration phase

Question 58

Cells save energy and materials by using many of the same enzymes for both _________ and _________. anabolism; catabolism metabolism; catabolism peptidoglycan; lipopolysaccharides ATP; NADPH

Answer 58

anabolism; catabolism

Question 59

Which of the following is the building structure for macromolecules? Multiple Choice Polymers Monomers Multimers Proteins

Answer 59

Monomers