chapter 3 (a) Flashcards
axial filament is another term for
endoflagellum
A periplasmic flagellum found in some spirochete bacteria is called a(n)
____ filament.
axial
Which appendages provide attachment points or channels, rather than motility? More than one answer may be correct.
a. flagella
b. axial filaments
c. pili
d. fimbriae
e. nanotubes
c, d, e
describe peptidoglycan structure
in gram positive cells: what two acids do peptidoglycan contain?
Contains teichoic acid and lipoteichoic acid
what do teichoic acid and lipoteichoic acid do
- Function in cell wall maintenance and enlargement
- Contribute to the acidic charge on the cell surface
in gram positive cells
in gram -negative cell walls how thick is the peptidoglycan layer ?
1 - 3mm
steps in a gram stain?
t/f only some bacterial cells can be gram stained
MOST ALL BACTERIA because most all have a cell wall
what is the most important stain
gram stain, most all bacteria can be stained because they contain a cell wall
Mycobacterium and Norcardia are examples of
acid fast bacteria
contain peptidoglycan and stain gram-positive, but bulk of cell wall is composed of unique lipids
acid fast bacteria Mycobacterium and Norcardia
where is Mycolic acid found
Found in the cell walls of acid-fast bacteria
what is Mycolic acid
Very-long-chain fatty acid
what does mycolic acid do
Makes bacteria highly resistant to certain chemicals and dyes and contributes to the pathogenicity of bacteria
Exhibit unusual adn chemially distinct cell walls
Archaea
some ______ have cell walls composed entirely of polysaccharides others have cell walls made of pure protein
archaea
____ lack true peptidoglucan structure
archaea cell wall
T/F ALL archea have a cell wall
some lack a cell wall entirely
T/F Mycobacterium adn Norcardia stain gram negative
False, they contain pepidoglycan and stain gram + but bulk of cell wall is compose of unique lipids (mycolic acid)
genus that naturally lack a cell wall
Mycoplasmas
sterols in this genus cell membrane stabilize the cell against lysis
Mycoplasmas ( no cell wall)
L forms
some bacteria that naturally have a cell wall but lose it during part of life cycle due to mutiations etc
t/f L forms play in a role in resistant antibiotics
true, role in persistent infections, no cell wall to kill
walking pneumonia is called
Mycoplasma pneumoniae
in gram negative cells, the outer membrane is similar to other membranes except it contains specialized polysaccharides and proteins caled _____ and ______
lipopolysaccharide (LPS) and Porin proteins
Lipopolysaccharide (LPS):
Signaling molecules and receptors
Endotoxin, lipid “A” find its eway to receptor cites that causes vaso dialation adn hypotension , also inflammation and feaver.
porin proteins
Special membrane channels that only the outer membrane allows certain chemicals to penetrate
controls what enters and exits cell and also in baceria resposible for energy production
cytoplasmic membrane structure
cytoplasmic membrane structure is a lipid by layer with proteins embedded serves as a site for (4)
energy reactions
nutrient processing
synthesis
regulates transport of nutrients and wastes
__________ is selectively permeable : special carrier machanisms for passage of most molecules.
(surrounds cell membrane, space between cytopalsmic membrane adn cell wall where many metablic functons occur. produces ATP and other functions
periplasmic space
gram positive bacteria is harder to kill than gram negative
false. gram - negative is harder to kill because extra membrane
t/fanything with lipid alcohol can kill gram negative
true. extra membrane to get through. need to be able to cross extra membrane to lyse (antibiotics)
alcohol swabs used to cleanse the skin before certain medical proceudres are abel to kill gram _____ bacteria
negative (disrupts outer membane).
treatment of infections cause by gram negative bacteria require drugs that can ____
cross the outer membrane.
the cytoplasm is ______% water
70-80% mostly cytosol.
the cytoplasm is made up of
sugars, amino acids, salts
The hereditary material of most bacteria exists in the
bacterial chromosome
DNA is aggregated in the
nucleoid
Nonessential pieces of DNA
Plasmids
Confer protective traits such as drug resistance and toxin and enzyme production, non essential but very benefitical for organism. code for drug resistance, chances to survive in different envionrmnt.
Plasmids
Ribosomes
Site of protein synthesis
Composed of rRNA (___%) and protein (_____%)
ribosomes ____ 60% rRNA , 40% protein
Consist of a large and small subunit ______ what sizes are each
ribosome, 30s (small) 50s (large)
ribosomes large and small subunit together equal _S
70s
Prokaryotic ribosome: ____S
Eukaryotic ribosome: _____S
Prokaryotic ribosome: 70S
Eukaryotic ribosome: 80S
Inclusion Bodies Used for (3)
Used for food storage
Pack gas into vesicles for buoyancy
Store crystals of iron oxide with magnetic properties
Bacterial microcompartments used for:
Packed full of enzymes designed to work together in biochemical pathways
Inclusion Bodies made from
polyphosphates or glycogen
microcompartments
protein structure that contains enzymes
cytoskeleton is in every bacterial cell
false
cytoskeleton is made from
long polymers of protein similar to eukaryotic cells for teh cytoskeleton
cytoskeleton is arranged in
helical ribbons around the cell
t/f archaea have no cytoskeleton
false - have been identified in archaea
t/f cytoskeleton is unique to non-eukaryotic cells,
true. potentially a target for antibiotic development.
dormant bodies of a bacterial cell
endospore
three genuses that produce endospores
Bacillus, Clostridium, and Sporosarcina
a metabolically active cell
vegetative cell
sporulation is induced by
environmental conditions
t/f Endospores resist extremes of heat, drying, freezing, radiation, and chemicals that would kill vegetative cells
true
Calcium and dipicolinic acid
are important parts of
endospores The presence of calcium and dipicolinic acid in endospores is vital for their resistance to environmental stresses and their ability to survive in harsh conditions. T
all hae in common: Bacillus anthracis: agent of anthrax
Clostridium tetani: cause of tetanus
Clostridium perfringens: cause of gas gangrene
Clostridium botulinum: cause of botulism
Clostridium difficile: “C. diff,” a serious gastrointestinal disease
ability to make endospores
agent of anthrax
Bacillus anthracis
cause of tetanus
Clostridium tetani
cause of gas gangrene
Clostridium perfringens
cause of botulism
Clostridium botulinum
Clostridium difficile
“C. diff,” a serious gastrointestinal disease
Compare and contrast the major features of archaea, bacteria, and eukaryotes.
Cell Type
Archaea: Prokaryotic (lack a nucleus and membrane-bound organelles).
Bacteria: Prokaryotic.
Eukaryotes: Eukaryotic (have a nucleus and membrane-bound organelles).
2. Cell Structure
Archaea:
Cell walls do not contain peptidoglycan; they may contain pseudopeptidoglycan or other polymers.
Membranes often have ether-linked lipids, which are more stable in extreme environments.
Bacteria:
Cell walls typically contain peptidoglycan.
Membranes have ester-linked lipids.
Eukaryotes:
Cell walls (if present, e.g., in plants and fungi) contain cellulose (plants) or chitin (fungi); animal cells do not have cell walls.
Membranes have ester-linked lipids.
3. Genetic Material
Archaea: Circular DNA, similar to bacteria, but with histone proteins associated with the DNA.
Bacteria: Circular DNA, usually a single chromosome, with no histones.
Eukaryotes: Linear DNA organized into multiple chromosomes, associated with histones.
4. Reproduction
Archaea: Asexual reproduction primarily through binary fission; some can also reproduce by budding.
Bacteria: Asexual reproduction mainly by binary fission; can exchange genetic material through horizontal gene transfer (transformation, transduction, conjugation).
Eukaryotes: Reproduce asexually (mitosis) and sexually (meiosis).
5. Size
Archaea: Generally similar in size to bacteria, typically 0.1 to 15 micrometers.
Bacteria: Usually range from 0.2 to 10 micrometers.
Eukaryotes: Generally larger, typically 10 to 100 micrometers (or larger in multicellular organisms).
6. Metabolism
Archaea: Diverse metabolic pathways; some are extremophiles (thermophiles, halophiles, methanogens).
Bacteria: Diverse metabolism, including aerobic, anaerobic, phototrophic, and chemotrophic processes.
Eukaryotes: Generally more complex metabolic processes; can be autotrophic (plants) or heterotrophic (animals, fungi).
7. Habitat
Archaea: Often found in extreme environments (hot springs, salt lakes), but also in more common habitats.
Bacteria: Ubiquitous; found in diverse environments, including soil, water, and within organisms.
Eukaryotes: Found in a wide range of habitats; includes unicellular (protists) and multicellular organisms (plants, animals, fungi).
t/f archea are more closely related to bacteria than eukarya
false - more closely related to eukarya, share rRNA sequences not found in bacteria, protein synthesis and ribosomal subunit structures are similar.
2 ways Archaea adn Eukarya are more similar than bacteria
share rRNA sequences not found in bacteria, protein synthesis and ribosomal subunit structures are similar
t/f archaea have an entirely unique sequences in rRNA
TRUE
t/f archaea and eukarya have the same mehtod of DNA compaction
FALSE- eukarya have a novel method of DNA compaction
T/F archaea contain unqiue membrane lipids, cell wall components and pilin proteins
TRUE
archaea are known as
extremophiles - extremely high or low temp, exremely high salt or acid concentrations, live on sulfur or methane,
some extremophiles live on teh human body and may be capable of disease
TRUE
Which of the following do members of the domains Bacteria and Archaea both possess?
A. Linear DNA
B. Nucleus
C. 70S ribosomes
D. Fatty acids with ether linkages
C. 70S ribosomes
Explanation:
A. Linear DNA: This is not correct, as both domains typically have circular DNA.
B. Nucleus: Neither bacteria nor archaea have a true nucleus; they are both prokaryotic.
C. 70S ribosomes: Correct, as both bacteria and archaea have 70S ribosomes, which are smaller than the 80S ribosomes found in eukaryotes.
D. Fatty acids with ether linkages: This is characteristic of archaea, but bacteria have fatty acids with ester linkages.
Comprehensive view of bacterial and archaeal (prokaryote) relatedness
Based on rRNA sequencing (Genomic sequencing)
Bergey’s Manual of Systematic Bacteriology:
Bergey’s Manual of Determinative Bacteriology:
Categorizes organisms based on traits commonly assayed in clinical, teaching, and research labs such as shape as seen in a microscope, or metabolic capabilities (what they need to grow)
Four major divisions of bacteria and archaea based on the nature of the cell wall:
Gracilicutes
Firmicutes
Tenericutes
Mendosicutes
Gracilicutes:
gram-negative with thin cell walls
Tenericutes
lack a cell wall and are soft
Firmicutes
gram-positive with thick, strong cell walls
Mendosicutes:
primitive cells with unusual cell walls and nutritional habits
a __________ Should share at least 95% of their genes as matches
bacterial species
A collection of bacterial cells, all of which share an overall similar pattern of traits
bacterial species
Subspecies, strain, or type:
Bacteria of the same species that have differing characteristics
Representatives of a species that stimulate a distinct pattern of antibody (serum) responses because of unique surface molecules
Serotype:
You identify a bacterium as gram negative using the Gram-stain method. In Bergey’s Manual of Determinative Bacteriology, this bacterium belongs to the _____.
A. gracilicutes
B. firmicutes
C. tenericutes
D. mendosicutes
A
The bacterial flagellum moves by Blank______.
a. expanding and contracting
b. rotating 360°
c. undulating back and forth
b
All of these appendages provide motility to bacteria except Blank______ and Blank______.
Multiple select question.
a. fimbriae
b. flagella
c. axial filaments
d. nanowires
a, d
The ability to move through self-propulsion is referred to as Blank______.
Multiple choice question.
a. adhesion
b. conjugation
c. mobility
d. motility
e. bioremediation
d. MOTILITY
Which three structures comprise a bacterial flagellum?
Multiple select question.
filament
periplasmic space
basal body
centrioles
hook
hook, filament, basal body
To determine whether bacterial cells are motile, they can be observed microscopically in a _____ drop slide.
hanging
Movement of the bacterial flagellum involves 360 rotation of two flagellar parts: the ___ and ____
hook and filament,
Counterclockwise rotation of the flagellum causes a bacterial cell to swim or Blank______ toward a stimulus, interrupted by clockwise rotation in which the cell Blank______ and changes its course.
run, tumbles
what is the space between the cell wall and cytoplasmic membrane?
periplasmic space
internal flagellum enclosed in the periplasmic space
internal flagellum - periplasmic flagella, axial filaments
The ability of a cell to move or self-propel through an aqueous environment is known as
motility, locomotion, or self-propulsion
The bacterial cellular appendages responsible for the mutual clinging of cells that lead to biofilm formation are Blank______.
fimbriae
conjugation
transfer of genes from cell to cell (mating)
pili conjugation only occurs in ____ cells
gram negative cells
t/f conjugation does not occur in gram + cells
false - conjugation occurs but not pilus conjugation
What is the glycocalyx?
an extracellular coating that provides protection to the cell
To protect the cell from dehydration and loss of nutrients, some bacteria are covered with a loose shield called a
slime layer
Nanotubes or nanowires are long extensions of the Blank______ that bacteria use as channels to transfer nutrients or electrons.
cytoplasmic membran
The colonization of nonliving materials like catheters, intrauterine devices, and metal pacemakers is the result of which bacterial structure?
Multiple choice question.
a. S layer
b. flagella
c. peptidoglycan
d. glycocalyx
d
t/f Bacteria that produce an S layer do so only when they are in a hostile environment.
true - Bacteria do not produce an S layer unless it is needed for protection.
The cell envelope is composed of the cytoplasmic ____ and the ____ and in some bacteria _____
cytoplasmic membrane, cell wall and outer membrane
t/f the glycogalyx surrounds the cell envelope
true
The structure that determines the shape of a bacterium and protects the cell from damage due to changes in osmotic pressure is the cell
__
wall
Streptococci in the mouth can produce a surface slime that permits attachment to teeth and results in the formation of Blank______.
Multiple choice question.
plaque
correct
cold sores
cavities
plaque - Cavities are the ultimate result of plaque formation, but the surface slime promotes the formation of plaque.
The glycocalyx is important in the ability of bacteria to cause infection because it Blank______. More than one answer may be correct.
Multiple select question.
a. promotes genetic transfer
b. allows for the formation of biofilms
c. allows the bacteria to adhere well to medical devices
d. allows the bacteria to move easily through the bloodstream
b,c
Peptidoglycan is composed of long glycan chains cross-linked by Blank______.
Multiple choice question.
monosaccharides
peptide fragments
crystal violet
disulfide bonds
peptide fragments
Peptidoglycan is a component of the cell wall in Blank______.
Multiple choice question.
a. bacteria
b. archaea
c. protozoans
d. fungi
a
Antibiotics of the penicillin class target the peptide cross-links in the
of the cell wall, causing it to disintegrate.
peptidoglycan
Which of the following are components of peptidoglycan? More than one answer may be correct.
Multiple select question.
a. short peptides
b. phospholipids
c. circular RNA
d. single-stranded DNA
e. sugar chains
f. monosaccharides
a,e
Tears and saliva contain an enzyme called
_____
that catalyzes the hydrolysis of glycan chains in peptidoglycan.
lysozyme , antibacterial enzyme that stops bacteria in water in our bodies
Antibiotics of the Blank______ class act on peptidoglycan, so that the cell wall is compromised and the cell will lyse.
Multiple choice question.
erythromycin
penicillin
tetracycline
fluoroquinoline
penicillin
Peptidoglycan is composed of long glycan chains cross-linked by Blank______.
Multiple choice question.
peptide fragments
monosaccharides
crystal violet
disulfide bonds
peptide fragments
peptide fragments
Which is the correct order of the four reagents of the Gram stain?
Multiple choice question.
crystal violet, alcohol, Gram’s iodine, safranin
Reason: Incorrect. Crystal violet is the initial or primary stain, followed by iodine, which “fixes” the CV in the cell. Gram negatives are then “decolorized” by alcohol and counter-stained with safranin.
Gram’s iodine, crystal violet, alcohol, safranin
Gram’s iodine follows crystal violet, as it “fixes” the CV in the cell.
crystal violet, Gram’s iodine, alcohol, safranin
correct
safranin, crystal violet, alcohol, Gram’s iodine
crystal violet, Gram’s iodine, alcohol, safranin
all bacteria contain a cell _____ but not all bacteria have a cell___
membrane, wall
Which staining technique allows differentiation of mycobacterial cells?
Multiple choice question.
negative stain
capsular stain
Gram stain
acid-fast stain
acid fast ( no cell wall)
Archaeal cell walls Blank______.
Multiple choice question.
may be made of polysaccharide or protein
have only thin protein coats like animal cell walls
contain cellulose like plant cell walls
contain peptidoglycan like bacterial cell walls
may be made of polysaccharide or protein
The Blank______ bacteria have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols.
Multiple choice question.
mycoplasma
another word for cell membrane
cytoplasmic membrane
what is the cytoplasmic membrane made up from?
phospholipids (lipids) 30-40% and proteins (60%-70%)
it is a lipid bilayer with proteins embedded.
explain the realtionship of Mycobacterium and Norcardia and gram staining
cell walls of these contain peptidoglycan and will stain gram -positive but the bulk o fcell wall is composed of lipids (one is called mycolic acid - contributes to pathogenicity of this group) thick waxy nature means thy are resistant to chemicals and dyes and instead acid fast stian (used to diagnose tuberculosis and leprosy
acid fast stain is used to diagnose _____ and ____
tuberculosis and leporsy
t/f No archeal cells have peptidoglycan cell walls
true- only bacteria
Which is more impervious to the action of antimicrobial chemicals?
Multiple choice question.
typical gram-negative bacteria
typical gram-positive bacteria
typical gram-negative. outer membrane contrinutes extra barrier making them resistant to some antimicrobial checmicals
The hereditary material of a typical bacterial cell is a single, circular molecule of DNA known as the bacterial____which is aggregated in the nucleoid.
chromosome
the bacterial chromosome is a long molecule of_____ stranded DNA that is formed into a ___ with no loose ends
double, circle
Plasmids typically carry which of the following genes? More than one answer is correct.
Multiple select question.
a. Nonessential
b. essential
c. Antibiotic resistance
d. Required
a, c
the____ _____ is an extremely long molecule of ____ stranded DNA that is tightly coiled around special basic ____ molecules so as to fit inside the cell
bacterial chromosome,
double
protein
chains of ribosomes are called
polysomes
the primary function of bacterial endospores?
reproduction
dispersal
survival
survival
ribosomes are formed by a combination of two components _____ and ______.
rRNA and proteins
Where are the bacterial ribosomes located? More than one answer may be correct.
Multiple select question.
a. attached to the cytoplasmic membrane
b. attached to the outer membrane
c. in the cytoplasm
d. in the periplasm
a, c,
show up as specks dispersed throughout cytoplasm and on cytoplasmic membrane. they are 60%rRNA (RNA) and 40%protein
whats process of endospore formation called
sporulation
arrow is pointing to?
a chromosome
b. endospore
c. microcompartment
b. endospore
The two phases of the life cycle of bacteria in the genera Bacillus, Clostridium, and Sporosarcina are Blank______ and Blank______.
Multiple select question.
vegetative cells
gram-negative
gram-positive
archaea
endospores
vegetative and endospore
three bacteria genus that create endospores
Bacillus, Clostridium, and Sporosarcina
Archaea that are adapted to growth at very low temperatures are called Blank______.
Multiple choice question.
methanogens
halophilic
psychrophilic
hyperthermophilic
psychrophilic
A type of extremophile that is able to flourish at high temperatures, such as those found in thermal heat vents and volcanic waters, is called a
hyperthermophile
Bergey’s Manual of Determinative Bacteriology classifies bacteria into taxonomic divisions such as the Gracilicutes and Firmicutes based on the nature of the cellular structure known as the
.
cell wall
Why is it difficult to group bacteria into species? More than one answer may be correct.
Multiple select question.
a. Bacteria are not alive and are not cells.
b. Bacterial cells can accept genetic material from other, sometimes unrelated cells.
c. Bacteria do not use a typical mode of sexual reproduction.
d. Bacteria can hybridize, thus making the definition of a species difficult or impossible.
e. Bacteria can alter their genetic makeup.
Bacterial cells can accept genetic material from other, sometimes unrelated cells.
Bacteria do not use a typical mode of sexual reproduction.
Bacteria can alter their genetic makeup.
bacteria cant hybridize, its a characterization of sexually reproducing organisms
The nature of which structure is used in the Bergey’s Manual of Determinative Bacteriology to divide bacteria and archaea into four major divisions?
Multiple choice question.
cell wall
DNA composition
type of ATP production
biochemical pathways
cell wall
A collection of bacterial cells, all of which share an overall similar pattern of traits, in contrast to other groups whose patterns differ significantly is called a bacterial ____
species
Bergey’s Manual of Blank______ Bacteriology is used by microbiologists whose primary interest is identification of prokaryotes, while Bergey’s Manual of Blank______ Bacteriology is used by those who are also interested in the evolutionary relationships of prokaryotes.
Determinative, Systemic
