Microbiology ch3 – Flashcards

question

The genus of bacteria that undergoes cell division in random planes, forming grape like clusters of round bacteria, are the __________. 

answer

staphylococci

question

Bacteria that do not have a fixed shape are said to be __________. 

answer

pleomorphic

question

 A branched network of hyphae formed by the Actinomycetes is called a __________.  

answer

mycelium

question

 Actinomycetes form long filaments called ___________.  

answer

hyphae

question

True or False

Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization. 

answer

TRUE

question

True Or False

The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.  

answer

FALSE

question

True or False

Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria. 

answer

FALSE

question

True or false

Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria. 

answer

FALSE

question

 Bacteria growing at lower temperatures have more saturated fatty acids in their membranes.  

answer

FALSE

question

When the cell wall is removed from a Gram-negative bacterium without removing the outer membrane, the resulting form is called a(n) __________.  

answer

spheroplast

question

Enzymes that are secreted out of the cell to aid in the acquisition and digestion of environmental nutrients are called __________.  

answer

exoenzymes

question

Molecules or regions of molecules that readily interact with water are said to be __________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.  

answer

hydrophilic

question

A __________ layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.  

answer

slime

question

A __________ is a polysaccharide layer that lies outside the cell wall and is not easily removed.  

answer

capsule

question

(p. 52)  _______ bind ferric iron and transport it into a bacterial cell.  

answer

siderophores

question

(p. 49)  Nutrients that are used by bacteria in relatively large amounts are _____.  

answer

macronutrients

question

T/F

(p. 42)  Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.  

answer

TRUE

question

(p. 52) You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____. 

 facillitated diffusion
micronutrient regulator
passive diffusion
group translocation

 
answer
group translocation
question

T/F

Growth factors cannot by synthesized by the bacteria that use them and include amino acids, pyrimidines, and vitamins.  

answer

TRUE

question

(p. 77)  Endospores are resistant to most environmental stressors because they have _____ complexed with calcium ions which stabilize DNA.  

answer

Dipicolinic acid

question

(p. 77)  Which of the following structures is NOT found in an endospore?  
capsule
coat
 core
exosporium 

answer
capsule 
question

T/F

If you remove the peptidoglycan layer from a Gram positive cell, it would still stain purple with a Gram stain.  

answer

FALSE

question

The most widely accepted current model for membrane structures is called the __________ model.  

answer

fluid mosaic

question

T/F

The layers of peptidoglycan of the bacterial cell wall can be cross-linked by peptide intrabridges or by direct cross-linking.  

answer

FALSE

question

T/F

Some photosynthetic bacteria produce gas vacuoles that regulate their buoyancy but contain no lipid. 

answer

TRUE

question

Intracellular granules of organic or inorganic material that are stockpiled by bacteria for future use are called __________.  

answer

inclusions

question

 Bacteria have a region of the cytoplasm known as the __________, which is not bounded by a membrane but contains the chromosome.  

answer

nucleoid

question

 Small circular DNA molecules capable of replicating and containing genes that are useful but not necessary to the bacterium are called __________.  

answer

plasmids

question

 Some species of aquatic bacteria use inclusion bodies known as ________ to orient themselves in Earth's magnetic field.  

answer

magnetosomes

question

_______ are the site of protein synthesis in the cell.  

answer

Ribosomes

question

T/F

 Sedimentation coefficients are proportional to the molecular weight of a particle and are not affected by the volume and shape of the particle.  

answer

FALSE

question

Bacterial flagella are composed of three parts: the ______ body, which is embedded in the cell, the hook, and the _______, which is the longest part of the flagellum.  

answer

basal, filament

question

Proteinacious projections from the surface of a bacterium that are used to mediate conjugation are called sex __________, whereas projections that mediate attachment to surfaces such as host cells are called __________.  

answer

pili, fimbriae

question

T/F

During the assembly of the flagellar filament, the flagellin protein monomers assemble at the cell proximal base of the flagellum. 

answer

FALSE

question

monotrichous

answer

a single flagellum

question

peritrichous

answer

a relatively even distribution of flagella over the entire surface of the bacterium  

question

lophotrichous

answer

a cluster of flagella at one or both ends of an organism

question

amphitrichous

answer

a single flagellum at each pole of an organism

question

T/F

The rotation of bacterial flagella is powered by ATP hydrolysis. 

answer

FALSE

question

The bacterium E. coli swims in a straight line, called a __________, for a few seconds; then it stops, tumbles, then swims away in a new direction.  

answer

run

question

 In many spirochetes, multiple flagella combine to form a bundle known as a(n) ____________ fibril, which winds around the cell and confers motility on the cell.  

answer

axial

question

__________ is the process through which endospores are formed within a vegetative cell. 

answer

Sporulation

question

 __________ is the main part of the process through which a vegetative cell is formed from an endospore.  

answer

Germination

question

The concept of a prokaryote was first fully outlined in 1962 by   

 Watson and Crick.
Stanier and Van Niel.
Hersey and Chase.
Gilbert and Cech.

 
answer
Stanier and Van Niel.
question

The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is  

cocci.
bacilli.
vibrio.
coccobacilli. 

answer
coccobacilli. 
question

Bacterial cells that are variable in shape are called 

 vibrio.
 pleomorphic.
coccobacilli.
hyphal.

answer
pleomorphic.
question

Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called 


 streptococci.
staphylococci.
 tetrads.
sarcinae.

 
answer
tetrads.
question

Flexible bacteria with a helical shape are called 
vibrios.
spirilla.
spirochetes.
coccobacilli.

answer
spirochetes.
question

Rigid bacteria with a helical cell shape are called 
vibrios.
 spirilla.
 spirochetes.
coccobacilli.

answer
spirilla.
question

Rigid bacteria with a helical cell shape are called 
vibrios.
 spirilla.
 spirochetes.
coccobacilli.

answer
spirilla.
question

The term used to describe bacteria that are shaped like curved rods is 
 coccus.
 bacillus.
vibrio.
coccobacillus.

answer
vibrio.
question

The term used to describe bacteria that are rod shaped is 
 coccus.
bacillus.
 vibrio.
coccobacillus.

answer
bacillus.
question

The term used to describe bacteria that have a spherical shape is 
coccus.
bacillus.
vibrio.
coccobacillus.

answer
coccus
question

The cytoplasmic membrane of bacteria 


retains the cytoplasm and its contents.
acts as a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others.
is the major site of ATP synthesis in aerobes.
all of the choices.

answer
all of the choices.
question

The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as 

 exotoxin.
teichoic acid.
murein.
endotoxin.

answer
endotoxin.
question

Which of the following is/are true of capsules? 


They help bacteria escape phagocytosis by host cells.
They retain water and help prevent desiccation of the bacteria.
They prevent entry of many bacterial viruses.
all of the choices.

answer
all of the choices.
question

Proteins that are loosely associated with the cytoplasmic membrane are called __________ proteins.  

peripheral
  integral
 external
internal 

answer
peripheral 
question

Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called __________ proteins. 

 peripheral
integral
 external
 internal

answer
integral
question

Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called 

 osmolysis.
 plasmolysis.
 hydrolysis.
hypertonolysis.

answer
plasmolysis.
question

Lipids with polar and nonpolar ends are said to be 

 amphipathic.
 amphibolic.
 bilateral.
none of the choices.

answer
amphipathic.
question

Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n) __________ environment. 

hypotonic
 isotonic
hypertonic
nonpolar

answer
isotonic
question

All of the following statements about the periplasmic space are true except:  

It is found only in gram-positive bacteria.
It is located between the plasma membrane and outer membrane of gram-negative bacteria.
It contains hydrolytic enzymes and binding proteins involved in nutrient acquisition.
All of the above are true. 

answer
 It is found only in gram-positive bacteria. 
question

Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape?  

  plasma membrane
  peptidoglycan
  capsule
gas vacuoles 

answer
peptidoglycan 
question

Sortase is a protein enzyme of bacteria that 

plays a key role in directing proteins to the periplasm.
catalyzes covalent attachment of some surface proteins to peptidoglycan.
directs secretion of proteins across the outer membrane.
functions by transporting flagellum proteins to their extracellular site of assembly.

answer
catalyzes covalent attachment of some surface proteins to peptidoglycan.
question

Which of the following is not true of bacterial plasmids? 

They can replicate independently of the chromosome.
They may carry genes for drug resistance.
They are required for host growth and/or reproduction.
They may carry genes that enhance survival of the bacterium under certain conditions.

answer
They are required for host growth and/or reproduction.
question

 Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient.  

answer

70S 

question

The type III bacterial protein secretion machinery: 


has a needlelike structure through which proteins are secreted.
includes structural features that may be evolutionarily related to the basal bodies of bacterial flagella.
is found in gram-negative bacteria.
all of the choices are correct.

answer
all of the choices are correct.
question

Export of flagellin subunits is mediated by  


  an apparatus in the basal body of the flagellum that is related to the type II secretion pathway.
  the type I secretion pathway.
  an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.
  none of the above. 

answer
an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.
question

The power used by most bacterial flagellar motors is produced by 

 synthesis of glucose.
 ATP hydrolysis.
 proton motive force (PMF).
 all of these.

answer
proton motive force (PMF).
question

Chemotaxis is a process by which bacteria 


 move toward an attractant or away from a repellent.
 avoid phagocytosis.
 respond metabolically to the presence of autoinducer molecules.
 move on solid surfaces by means of type IV fimbriae.

answer
move toward an attractant or away from a repellent.
question

Twitching or gliding motility involves  


  type IV pili.
  axial fibrils.
  movement of slime.
  both type IV pili and movement of slime can be involved in twitching or gliding motility. 

answer
both type IV pili and movement of slime can be involved in twitching or gliding motility. 
question

 Endospores represent a challenge to the fields of industrial and medical microbiology because

they are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive.
 endospore-forming organisms are often dangerous pathogens.
endospores are significantly smaller than vegetative cells.
 endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

answer
endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.
question

Elements that are required in relatively large amounts by microorganisms are called 
 multivitamins.
 meganutrients.
 macronutrients.
 macromolecules.

answer
macronutrients.
question

Which of the following is not considered a macronutrient? 
 carbon (C)
 calcium (Ca)
 potassium (K)
 cobalt (Co)

answer
cobalt (Co)
question

Which of the following is not considered a micronutrient? 

 manganese (Mn)
 magnesium (Mg)
 zinc (Zn)
 copper (Cu)

answer
magnesium (Mg)
question

T/F

The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components. 

answer
TRUE
question

T/F

Zinc (Zn) is considered a macronutrient. 

answer

FALSE

question

T/F

 

Copper (Cu) is considered a micronutrient. 

answer
TRUE
question

T/F

Sulfur can be obtained from inorganic sources only. 

answer
FALSE
question

T/F

Phosphorus can be obtained from organic sources only. 

answer
FALSE
question

T/F

Nitrogen can be obtained from either organic or inorganic sources. 

answer
TRUE
question

__________ __________ are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism. (2 words)  

answer
Growth factors
question

Which of the following is not a major class of growth factors? 

 amino acids
 purines and pyrimidines
 vitamins
 nucleic acids

answer
nucleic acids
question

Small organic molecules called __________ function as enzyme cofactors.  


answer
vitamins
question

A wide variety of microorganisms are commercially used to manufacture _________ for human consumption. 


 vitamins
 sugars
 fatty acids
 none of the choices

answer
vitamins
question

Many bacteria facilitate the uptake of iron by secreting low molecular weight molecules, called ___________, to form complexes with the iron that can then be readily transported into the cell. 

answer
siderophores
question

Transport of two different substances can be linked. If the transport is in the same direction it is called __________; if the transport is in opposite directions it is called __________. 

answer
symport, antiport
question

_________ are carrier proteins embedded in the membrane that increase the rate of diffusion of specific molecules across selectively permeable membranes. 

answer
Permeases
question

T/F

Organisms usually have only a single transport system for any nutrient. 

answer
FALSE
question

 Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways. 

answer
TRUE
question

T/F

Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances. 

answer
TRUE
question

 

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells. 

answer
question

T/F

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells. 

answer
TRUE
question

Which of the following processes can be used to bring nutrients into a cell against a concentration gradient? 

 Active transport.
 Facilitated diffusion.
 Passive diffusion.
 Active transport and facilitated diffusion.

answer
Active transport.
question

Which of the following is a characteristic of active transport? 

 Saturable uptake rate.
 Use of ATP or a proton gradient as a source of metabolic energy.
 Can move materials against a concentration gradient.
 All of the choices.

answer
All of the choices.
question

The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called 

facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
active transport.
question

The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of a carrier molecule embedded in the membrane is called 

 facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
facilitated diffusion.
question

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called 

 facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
passive diffusion.
question

Nutrients can be concentrated from dilute solutions by 

 pinocytosis.
 endocytosis.
 active transport and group translocation.
 electron transport.

answer
active transport and group translocation.
question

__________ membranes allow some molecules to pass but not others. 

 Permeable
 Inverted monolayer
 Selectively permeable
 Impermeable

answer
Selectively permeable
1 of

Unlock all answers in this set

Unlock answers
question

The genus of bacteria that undergoes cell division in random planes, forming grape like clusters of round bacteria, are the __________. 

answer

staphylococci

question

Bacteria that do not have a fixed shape are said to be __________. 

answer

pleomorphic

question

 A branched network of hyphae formed by the Actinomycetes is called a __________.  

answer

mycelium

question

 Actinomycetes form long filaments called ___________.  

answer

hyphae

question

True or False

Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization. 

answer

TRUE

question

True Or False

The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.  

answer

FALSE

question

True or False

Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria. 

answer

FALSE

question

True or false

Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria. 

answer

FALSE

question

 Bacteria growing at lower temperatures have more saturated fatty acids in their membranes.  

answer

FALSE

question

When the cell wall is removed from a Gram-negative bacterium without removing the outer membrane, the resulting form is called a(n) __________.  

answer

spheroplast

question

Enzymes that are secreted out of the cell to aid in the acquisition and digestion of environmental nutrients are called __________.  

answer

exoenzymes

question

Molecules or regions of molecules that readily interact with water are said to be __________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.  

answer

hydrophilic

question

A __________ layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.  

answer

slime

question

A __________ is a polysaccharide layer that lies outside the cell wall and is not easily removed.  

answer

capsule

question

(p. 52)  _______ bind ferric iron and transport it into a bacterial cell.  

answer

siderophores

question

(p. 49)  Nutrients that are used by bacteria in relatively large amounts are _____.  

answer

macronutrients

question

T/F

(p. 42)  Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.  

answer

TRUE

question

(p. 52) You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____. 

 facillitated diffusion
micronutrient regulator
passive diffusion
group translocation

 
answer
group translocation
question

T/F

Growth factors cannot by synthesized by the bacteria that use them and include amino acids, pyrimidines, and vitamins.  

answer

TRUE

question

(p. 77)  Endospores are resistant to most environmental stressors because they have _____ complexed with calcium ions which stabilize DNA.  

answer

Dipicolinic acid

question

(p. 77)  Which of the following structures is NOT found in an endospore?  
capsule
coat
 core
exosporium 

answer
capsule 
question

T/F

If you remove the peptidoglycan layer from a Gram positive cell, it would still stain purple with a Gram stain.  

answer

FALSE

question

The most widely accepted current model for membrane structures is called the __________ model.  

answer

fluid mosaic

question

T/F

The layers of peptidoglycan of the bacterial cell wall can be cross-linked by peptide intrabridges or by direct cross-linking.  

answer

FALSE

question

T/F

Some photosynthetic bacteria produce gas vacuoles that regulate their buoyancy but contain no lipid. 

answer

TRUE

question

Intracellular granules of organic or inorganic material that are stockpiled by bacteria for future use are called __________.  

answer

inclusions

question

 Bacteria have a region of the cytoplasm known as the __________, which is not bounded by a membrane but contains the chromosome.  

answer

nucleoid

question

 Small circular DNA molecules capable of replicating and containing genes that are useful but not necessary to the bacterium are called __________.  

answer

plasmids

question

 Some species of aquatic bacteria use inclusion bodies known as ________ to orient themselves in Earth's magnetic field.  

answer

magnetosomes

question

_______ are the site of protein synthesis in the cell.  

answer

Ribosomes

question

T/F

 Sedimentation coefficients are proportional to the molecular weight of a particle and are not affected by the volume and shape of the particle.  

answer

FALSE

question

Bacterial flagella are composed of three parts: the ______ body, which is embedded in the cell, the hook, and the _______, which is the longest part of the flagellum.  

answer

basal, filament

question

Proteinacious projections from the surface of a bacterium that are used to mediate conjugation are called sex __________, whereas projections that mediate attachment to surfaces such as host cells are called __________.  

answer

pili, fimbriae

question

T/F

During the assembly of the flagellar filament, the flagellin protein monomers assemble at the cell proximal base of the flagellum. 

answer

FALSE

question

monotrichous

answer

a single flagellum

question

peritrichous

answer

a relatively even distribution of flagella over the entire surface of the bacterium  

question

lophotrichous

answer

a cluster of flagella at one or both ends of an organism

question

amphitrichous

answer

a single flagellum at each pole of an organism

question

T/F

The rotation of bacterial flagella is powered by ATP hydrolysis. 

answer

FALSE

question

The bacterium E. coli swims in a straight line, called a __________, for a few seconds; then it stops, tumbles, then swims away in a new direction.  

answer

run

question

 In many spirochetes, multiple flagella combine to form a bundle known as a(n) ____________ fibril, which winds around the cell and confers motility on the cell.  

answer

axial

question

__________ is the process through which endospores are formed within a vegetative cell. 

answer

Sporulation

question

 __________ is the main part of the process through which a vegetative cell is formed from an endospore.  

answer

Germination

question

The concept of a prokaryote was first fully outlined in 1962 by   

 Watson and Crick.
Stanier and Van Niel.
Hersey and Chase.
Gilbert and Cech.

 
answer
Stanier and Van Niel.
question

The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is  

cocci.
bacilli.
vibrio.
coccobacilli. 

answer
coccobacilli. 
question

Bacterial cells that are variable in shape are called 

 vibrio.
 pleomorphic.
coccobacilli.
hyphal.

answer
pleomorphic.
question

Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called 


 streptococci.
staphylococci.
 tetrads.
sarcinae.

 
answer
tetrads.
question

Flexible bacteria with a helical shape are called 
vibrios.
spirilla.
spirochetes.
coccobacilli.

answer
spirochetes.
question

Rigid bacteria with a helical cell shape are called 
vibrios.
 spirilla.
 spirochetes.
coccobacilli.

answer
spirilla.
question

Rigid bacteria with a helical cell shape are called 
vibrios.
 spirilla.
 spirochetes.
coccobacilli.

answer
spirilla.
question

The term used to describe bacteria that are shaped like curved rods is 
 coccus.
 bacillus.
vibrio.
coccobacillus.

answer
vibrio.
question

The term used to describe bacteria that are rod shaped is 
 coccus.
bacillus.
 vibrio.
coccobacillus.

answer
bacillus.
question

The term used to describe bacteria that have a spherical shape is 
coccus.
bacillus.
vibrio.
coccobacillus.

answer
coccus
question

The cytoplasmic membrane of bacteria 


retains the cytoplasm and its contents.
acts as a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others.
is the major site of ATP synthesis in aerobes.
all of the choices.

answer
all of the choices.
question

The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as 

 exotoxin.
teichoic acid.
murein.
endotoxin.

answer
endotoxin.
question

Which of the following is/are true of capsules? 


They help bacteria escape phagocytosis by host cells.
They retain water and help prevent desiccation of the bacteria.
They prevent entry of many bacterial viruses.
all of the choices.

answer
all of the choices.
question

Proteins that are loosely associated with the cytoplasmic membrane are called __________ proteins.  

peripheral
  integral
 external
internal 

answer
peripheral 
question

Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called __________ proteins. 

 peripheral
integral
 external
 internal

answer
integral
question

Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called 

 osmolysis.
 plasmolysis.
 hydrolysis.
hypertonolysis.

answer
plasmolysis.
question

Lipids with polar and nonpolar ends are said to be 

 amphipathic.
 amphibolic.
 bilateral.
none of the choices.

answer
amphipathic.
question

Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n) __________ environment. 

hypotonic
 isotonic
hypertonic
nonpolar

answer
isotonic
question

All of the following statements about the periplasmic space are true except:  

It is found only in gram-positive bacteria.
It is located between the plasma membrane and outer membrane of gram-negative bacteria.
It contains hydrolytic enzymes and binding proteins involved in nutrient acquisition.
All of the above are true. 

answer
 It is found only in gram-positive bacteria. 
question

Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape?  

  plasma membrane
  peptidoglycan
  capsule
gas vacuoles 

answer
peptidoglycan 
question

Sortase is a protein enzyme of bacteria that 

plays a key role in directing proteins to the periplasm.
catalyzes covalent attachment of some surface proteins to peptidoglycan.
directs secretion of proteins across the outer membrane.
functions by transporting flagellum proteins to their extracellular site of assembly.

answer
catalyzes covalent attachment of some surface proteins to peptidoglycan.
question

Which of the following is not true of bacterial plasmids? 

They can replicate independently of the chromosome.
They may carry genes for drug resistance.
They are required for host growth and/or reproduction.
They may carry genes that enhance survival of the bacterium under certain conditions.

answer
They are required for host growth and/or reproduction.
question

 Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient.  

answer

70S 

question

The type III bacterial protein secretion machinery: 


has a needlelike structure through which proteins are secreted.
includes structural features that may be evolutionarily related to the basal bodies of bacterial flagella.
is found in gram-negative bacteria.
all of the choices are correct.

answer
all of the choices are correct.
question

Export of flagellin subunits is mediated by  


  an apparatus in the basal body of the flagellum that is related to the type II secretion pathway.
  the type I secretion pathway.
  an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.
  none of the above. 

answer
an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.
question

The power used by most bacterial flagellar motors is produced by 

 synthesis of glucose.
 ATP hydrolysis.
 proton motive force (PMF).
 all of these.

answer
proton motive force (PMF).
question

Chemotaxis is a process by which bacteria 


 move toward an attractant or away from a repellent.
 avoid phagocytosis.
 respond metabolically to the presence of autoinducer molecules.
 move on solid surfaces by means of type IV fimbriae.

answer
move toward an attractant or away from a repellent.
question

Twitching or gliding motility involves  


  type IV pili.
  axial fibrils.
  movement of slime.
  both type IV pili and movement of slime can be involved in twitching or gliding motility. 

answer
both type IV pili and movement of slime can be involved in twitching or gliding motility. 
question

 Endospores represent a challenge to the fields of industrial and medical microbiology because

they are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive.
 endospore-forming organisms are often dangerous pathogens.
endospores are significantly smaller than vegetative cells.
 endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

answer
endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.
question

Elements that are required in relatively large amounts by microorganisms are called 
 multivitamins.
 meganutrients.
 macronutrients.
 macromolecules.

answer
macronutrients.
question

Which of the following is not considered a macronutrient? 
 carbon (C)
 calcium (Ca)
 potassium (K)
 cobalt (Co)

answer
cobalt (Co)
question

Which of the following is not considered a micronutrient? 

 manganese (Mn)
 magnesium (Mg)
 zinc (Zn)
 copper (Cu)

answer
magnesium (Mg)
question

T/F

The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components. 

answer
TRUE
question

T/F

Zinc (Zn) is considered a macronutrient. 

answer

FALSE

question

T/F

 

Copper (Cu) is considered a micronutrient. 

answer
TRUE
question

T/F

Sulfur can be obtained from inorganic sources only. 

answer
FALSE
question

T/F

Phosphorus can be obtained from organic sources only. 

answer
FALSE
question

T/F

Nitrogen can be obtained from either organic or inorganic sources. 

answer
TRUE
question

__________ __________ are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism. (2 words)  

answer
Growth factors
question

Which of the following is not a major class of growth factors? 

 amino acids
 purines and pyrimidines
 vitamins
 nucleic acids

answer
nucleic acids
question

Small organic molecules called __________ function as enzyme cofactors.  


answer
vitamins
question

A wide variety of microorganisms are commercially used to manufacture _________ for human consumption. 


 vitamins
 sugars
 fatty acids
 none of the choices

answer
vitamins
question

Many bacteria facilitate the uptake of iron by secreting low molecular weight molecules, called ___________, to form complexes with the iron that can then be readily transported into the cell. 

answer
siderophores
question

Transport of two different substances can be linked. If the transport is in the same direction it is called __________; if the transport is in opposite directions it is called __________. 

answer
symport, antiport
question

_________ are carrier proteins embedded in the membrane that increase the rate of diffusion of specific molecules across selectively permeable membranes. 

answer
Permeases
question

T/F

Organisms usually have only a single transport system for any nutrient. 

answer
FALSE
question

 Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways. 

answer
TRUE
question

T/F

Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances. 

answer
TRUE
question

 

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells. 

answer
question

T/F

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells. 

answer
TRUE
question

Which of the following processes can be used to bring nutrients into a cell against a concentration gradient? 

 Active transport.
 Facilitated diffusion.
 Passive diffusion.
 Active transport and facilitated diffusion.

answer
Active transport.
question

Which of the following is a characteristic of active transport? 

 Saturable uptake rate.
 Use of ATP or a proton gradient as a source of metabolic energy.
 Can move materials against a concentration gradient.
 All of the choices.

answer
All of the choices.
question

The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called 

facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
active transport.
question

The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of a carrier molecule embedded in the membrane is called 

 facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
facilitated diffusion.
question

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called 

 facilitated diffusion.
 osmosis.
 passive diffusion.
 active transport.

answer
passive diffusion.
question

Nutrients can be concentrated from dilute solutions by 

 pinocytosis.
 endocytosis.
 active transport and group translocation.
 electron transport.

answer
active transport and group translocation.
question

__________ membranes allow some molecules to pass but not others. 

 Permeable
 Inverted monolayer
 Selectively permeable
 Impermeable

answer
Selectively permeable