micro test 2
the LPS layer in gram-negative cell walls releases ________ that cause _____________ a. enzymes, pain b. endotoxins, fever c. techoic acid, inflammation d. phosphates, lysis
b. endotoxins, fever
if you gram stain a culture and see purple circles arranged in chians, you would call them :
gram-positive streptococci
gram positive cell walls __________.
have a thick layer of peptidoglycan
in what way are the spirochete flagella unusual? how do spirochetes move?
have periplasmic flagella. they move by twisting and flexing
storage structure
inclusions
small circular piece of DNA that carries non-essential genes
plasmid
if a bacterial cell lost its ribosomes, it would no linger be able to _______.
produce proteins
organisms that lack membrane-bound organelles and a nuclear membrane
prokaryotes
all organisms are made up of cells. what are the two fundamental types of cells?
prokaryotic and eukaryotic cells
to which taxonomic group do cyanobacteria belong?
domain bacteria
what is an endospore?
dormant form of bacteria that is resistant to most forms of environmental stress.
Which stain is used to distinguish differences between the cell walls of medically important bacteria?
gram stain
which bacteria are generally harder to kill- gram negative or gram positive?
gram-negative
Reproduction
1. binary fission 2. sexual or asexual processes
list the three most commonly seen bacterial cell shapes.
1. coccus (round) 2. bacillus (rod) 3. spirillum (spiral)
metabolism
1. enzymes 2. synthesis reactions 3. ribosomes
what are the seven basic characteristics that living things share?
1. growth and development 2. reproduction and heredity 3. metabolism 4. movement 5. cell support 6. protection and storage 7. transport systems In and out of a cell
An example of a glycocalyx is a. capsule b. pili c. outer membrane d. cell wall
a. capsule
give two reasons why microbiologists are concerned with classifying bacterial groups?
a. classification makes identification easier b. classification enables scientists to study relationships between bacterial groups
a capsule is used by bacterial cells for all of the following except: a. conjugation b. protection against phagocytes c. adhering to surfaces d. formation of biofilms
a. conjugation
which of the following bacteria are photosynthetic? a. cyanobacteria b. chlamydia c. pseudomonas d. treponema
a. cyanobacteria
the major locomotor in bacteria are a. flagella b. pili c. fimbriae d. cilia
a. flagella
appendages serve two generalized functions for bacteria. what are they? a. b.
a. motility b attachment
list and describe four separate functions of bacterial cell membranes a. b. c. d.
a. selectively permeable barrier and transport functions b. metabolism (electron transport chain) c. photosynthesis (pigments) d. synthesis of cell walls components
what is an acid-fast stain used for and which species of bacteria are acid-fast?
acid-fast stains identify bacteria with a thick waxy coat , such as mycobacteria and nocardia
filaments that are found in the cytosol and maintain cell shape
actin
what is the difference between pili and fimbriae? both are used for __________. pili are used for _____________
adhesion; conjugation
domain of prokaryotes that has many extremophiles
archaea
which prokaryotic domain is most closely related to eukaryotes?
archaea
how do chemical attractants affect the tumble/run cycle of a motile bacterial cell?
attractants inhibit the tumble cycle
which of the following prokaryotes lacks cell walls? a. rickettsias b. mycoplasmas c. Mycobacterium d. archaea
b. mycoplasmas
which of the following is present in both gram-positive and gram-negative cell walls? a. outer membrane b. peptidoglycan c. teichoic acid d. lipopolysaccharides
b. peptidoglycan
which of the following structures is not found in the cell envelope of a bacterial cell? a. cell wall b. ribosomes c. capsule d. glycocalyx
b. ribosomes
name two bacteria that form endospores
bacillus species and Clostridium species
how are the actions of lysozyme and penicillin similar?
both lysozyme and penicillin cause disruption of the cell wall by targeting peptidoglycan
bacterial plasmids will likely carry all the following EXCEPT: a. the gene to use a different sugar source b. antibiotic resistance genes c. genes for proteins required in metabolism d. all of these are commonly seen on plasmids
c. genes for proteins required in metabolism
pili are appendages in _______ bacteria that serve as a means of ______ a. gram positive; genetic change b. gram positive; attachment c. gram negative; genetic change d. gram negative; protection
c. gram negative; genetic change
which of the following is a primary bacterial cell wall function? a. transport b. motility c. support d. adhesion
c. support
which of the following statements is FALSE, concerning bacterial cell walls? a. they have peptidoglycan b. they give cells their shape c. they protect the cell from hypertonic lysis d. they are the target of penicillin action
c. they protect the cell from hypertonic lysis
which structure is not a component of all cells? a. cell wall b. cell membrane c. genetic material d. ribosomes
cell wall
cell support and protection
cell walls
there are two structures made of DNA in the bacterial cell. which is larger and contains essential genes?
chromosomes
there are two structures made of DNA in the bacterial cell. what are they?
chromosomes and plasmids
heredity
chromosomes or plasmids
movement
cilia or flagella
viruses are not considered living things because a. they are not cells b. they cannot reproduce by themselves c. they lack metabolism d. all of these are correct
d. all of these are correct
which of the following is not found in all bacterial cells? a. cell membrane b. a nucleoid c. ribosomes d. cytoskeleton
d. cytoskeleton
which group of bacteria have periplasmic flagella? a. bacilli b. cocci c. vibrio d. spirochetes
d. spirochetes
form of bacteria that is resistant to environmental stress
endospore
phylogenetic classification schemes group bacteria based on _____________
evolutionary relationships
archaeabacteria include:
extremophiles
endospores are used by some bacterial species to reproduce. true/ false
false
smooth, encapsulated bacteria are generally less pathogenic than are rough bacterial strains. true/flase
false
Which phylum contains bacteria with a gram-positive cell wall?
firmicutes
appendages used for motility
flagella
external structure - either slime layer capsule
glycocalyx
which bacterial structure is most directly involved in the formation of biofilms?
glycocalyx
sum of all the chemical reactions in a cell
metabolism
a flagellum is used by a bacterial cell for:
motility
group of bacteria that lack a cell wall and have sterols in their plasma membrane
mycoplasma
why do mycoplasmal cell membranes contain high levels of sterol molecules?
mycoplasmas lack a cell wall and use sterols to strengthen their cell membranes
are endospores used for reproduction?
no
there are two structures made of DNA in the bacterial cell. which genes are commonly found on plasmids?
non essential
what is peptidoglycan and where is it found in bacterial cells?
peptidoglycan is a polymer of long chains of sugar molecules joined by short peptide chains. it provides support and protection from lysis due to osmotic pressure.
polymer of sugars linked together with short peptide chains
peptidogylcan
phenetic classification schemes group based on__________
phenotype or metabolic characteristics
appendages required for conjugation
pili
color of stained gram-positive cells
purple
what gene sequences are commonly used to compare and classify newly described bacteria?
rRNA
Bacteria are taxonomically classified by __________.
rRNA Absequence similarity
what is the function of ribosomes?
required for protein synthesis
a flagellated bacterial cell moving toward a food source will ________:
run more than tumble
transport
semipermeable membranes
periplasmic flagella are found in _________
spirochetes
what is a strain of bacteria?
sub-pieces of a particular type of bacteria.
bacterial endospores function in _________
survival
the major difference between a spirochete and spirillum is ____________
the nature of motility