T/F bacteria are the smallest living cells
True
T/Fbacteria range from 0.1 to 10 um
True
Are there cytoplasmic organelles in bacteria
no
Do gram - or gram + have an outer membrane
gram negative
T/F a capsule is part of a cell envelope
false
T/f the envelope of gram negative bacteria contain an outer membrane
true
does the cell membrane of bacteria contain sterols
no
what is the only bacteria that contain sterols
mycoplasma
T/F the cell membrane is not permeable
false, it is semi permeable
Does cell membrane contain more lipids or proteins?
It is semi-permeable; consists of 70% protein and 30% phospholipid.
Where is the electron transport system located in bacteria ?
cell membrane
the mitochondria in eukaryotic cells is synonomous with what structure in bacteria
cell wall
proteins that function in chemotaxis and transport are located on what region of the cell
cell wall
T/F The cytoplasmic membranes of gram-positive and gram-negative cells are similar in composition and
function.
True
Do gram positive or gram negative bacteria have an outer membrane
gram negative
What is the function of the outer membrane
it is an asymmetric lipid bilayer providing protection to the cell;
What composes the outer and inner layer of the outer membrane
outer most layer of outer membrane is composed of lipopolysaccharide (LPS) and
is called endotoxin; inner layer of outer membrane is composed of phospholipid
another word for endotoxin is
LPS
Do gram positive or gram negative bacteria have LPS
Gram negative . ( remember its only on gram negative because they have an outer membrane )
outer membrane proteins are known as
porins
T/F Outer membrane proteins (porins) allow for diffusion of small hydrophobic molecules through the membrane
False! Outer membrane proteins (porins) allow for diffusion of small hydropHILLIC
molecules through the
membrane
What 3 things make up LPS ?
- LPS consists of 3 component parts: somatic O antigens, core polysaccharide and Lipid A.
somatic O antigens, core polysaccharide and Lipid A. make up what structure?
LPS
What is responsible for the toxity of LPS
Lipid A
What is responsible for distinguish serotypes of a species and responsible for the antigenicity of LPS?
Somatic O antigens
What are some Pathophysiologic effects of LPS
Pathophysiologic effects of LPS include fever (pyrogenic) and shock; B cell activation; the release of cytokines from macrophages; Shwartzman reaction, and death from massive organ dysfunction
What 2 sugars make up peptodiglycan ?
N-acetylglucosamine and N-acetylmuramic acid.
A tetrapeptide is attached to
N-acetylmuramic Acid or N-acetylglucosamineacid residue?
N-acetylmuramic Acid
Name 2 functions of peptodiglycan
peptidoglycan protects cells from osmotic lysis and provides cell shape.
about how many layers peptodiglycan do we see in gram positive bacteria
40
how about many layers of peptodiglycan do we see in gram negative bacteria
1-2 layers
Name 2 places where we can see lysozyme
tears and saliva
What enzyme can disrupt NAG & NAM
lysozyme
what are the 3 locations that peptodiglycan biosnthesis takes place
cytoplasm, membrane, and the wall
another word for cross linking is …
transpeptidation
another word for transpeptidation is
crosslinking
another word for penicillin binding proteins is
Transpeptidases
inhibition of transglycosylation and transpeptidation is caused by
vancomycin
what does vancomycin do
inhibits transglycosylation and transpeptidation
_________ insert newly made peptidoglycan
monomers into pre-existing peptidoglycan in the wall and links together NAG and NAM residues by β 1,4
linkages
transglycosidases insert newly made peptidoglycan
monomers into pre-existing peptidoglycan in the wall and links together NAG and NAM residues by β 1,4
linkages
What kind of linkages do we see in NAG & NAM
β 1,4
name an enzyme that can disrupt the linkage between NAG and NAM residues.
Lysozyme (in tears, saliva)
T/F Peptidoglycan biosynthesis takes place in 3 locations: cytoplasm, membrane, and the wall.
True!
List 2 things that inhibit transpeptidation
penicillin and cephalosporins;
What is transglycosilation
insertion of newly made peptidoglycan
monomers into pre-existing peptidoglycan
T/F vancomycin inhibits transglycosylation and transpeptidation;
True
What does vancomyocin inhibit
transglycosylation and transpeptidation;
a membrane phospholipid which translocates newly made peptidoglycan across the
Membrane to be inserted into pre-existing peptidoglycan is known as …
Bactoprenol
regeneration of bactoprenol phosphate from bactoprenol pyrophosphate is inhibited by what antibiotic
Bacitracin
list 3 wall-less bacteria
Wall-less bacteria include: Mycoplasma sp. and protoplasts and spheroplasts;
are protoplasts derived from gram + or gram - bacteria
gram positive
describe how protoplasts are generated
protoplasts are derived from
gram-positive bacteria when treated with penicillin and lysozyme under hypertonic conditions;
are spheroplasts derived from gram positive or gram negative bacteria
gram negative
Are teichoic acids found on gram + or gram -
Teichoic acids are found in gram-positive bacteria only and
T/F Teichoic acids are found on both gram + /-
FALSE! only found on gram positive
are teichoic acids found on NAG or NAM?
NAM
list 2 things that teichoic acids play a role in
involved in cell adhesion, activation of complement, and are antigenic.
mediate adherence/attachment of bacteria to host cells; most important virulence factor for Neisseria
gonorrhoeae. What cell surface component is this?
Pilli
T/F Pili undergo phase variation and antigenic variation; important in the evasion of host immune system.
True!
– role in cell adherence; prevents phagocytosis (anti-phagocytic); most important virulence factor for Streptococcus pneumoniae; consists of K antigens. What cell surface structure is this?
Capsule
What is the quellung reaction?
The Quellung reaction is used to detect the presence of capsules on cells.
What is the name of the reaction that is used to determine the presences of a capsule on a cell ?
The Quellung reaction
Mediate cell motility and movement during (chemotaxis) which is the movement of bacteria in specific directions in response to environmental stimuli. What cell surface structure is this?
Flagella
T/F Flagella are antigenic and consist of K antigens;
there is a simple 2 component signaling pathway involved in chemotaxis.
FALSE! They have H ANTIGENS, the CAPSULE has K antigens
breakdown of glucose in the absence of oxygen is known as
Fermentation
How many ATP are generated in Lactic Acid Fermentation?
2 ATP
How many ATP are generated in mixed acid fermentation
3 ATP
How many ATP are generated in lactic acid fermentation
2 ATP
What is the mechanism of energy generation in fermentation
substrate level
In general most fermentations generated how much ATP
2
-breakdown of glucose in the presence of oxygen is known as
-Aerobic respiration
a PO ratio of 3 generates how many ATP in bacteria undergoing aerobic respiration
38 ATP
A PO ratio of 2 will generate how many ATP undergoing aerobic respiration
26 ATP
The mechanism of energy generation in Aerobic respiration is
Oxidative phosphorylation
What is the terminal electron acceptor in Aerobic respiration
Oxygen is the terminal electron acceptor.
energy released during electron transport ,which is
used by the cell to make ATP is known as …
Proton motive force (pmf)
the number of ATPs generated per oxygen atom consumed or ratio of phosphates incorporated into
ATP to oxygen atoms reduced to water this ratio of known as
P/0 ratio
more efficient than fermentation but less efficient than aerobic respiration because
fewer ATPs are produced; compounds other than oxygen are used as terminal electron acceptors (nitrate,
sulfate). This is known as..
-Anaerobic respiration
The bacteria that are pathogenic to man are known as
-Heterotrophs
bacteria that require organic form of carbon (glucose) are considered
-Heterotrophs
bacteria that use inorganic form of carbon (CO2) are considered
autotrophs
give an example of inorganic carbon
co2
give an example of organic carbon
glucose
give an example of inorganic carbon
c02
strict aerobe / obligate aerobe
An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy
strict anaerobes
Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen
facultative anaerobe
A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent
aerotolerant
Aerotolerant anaerobes use fermentation to produce ATP. They do not utilize oxygen, but they can protect themselves from reactive oxygen molecules. In contrast, obligate anaerobes can be harmed by reactive oxygen molecules.
microaerophilic organisms
A microaerophile is a microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere.
aerobic, facultative anaerobic, and microaerophilic bacteria all possess what 2 enzyme for energy generation
possess superoxide dismutase and catalase
Aerotolerant anaerobes such as streptococci possess what 2 enzymes for energy generation ?
Aerotolerant anaerobes such as streptococci possess superoxide dismutase and peroxidase instead of catalase.
Do have aerotolerant anaerobes have catalase?
They are catalase negative and
carry out a fermentative metabolism even in the presence of oxygen.
T/F Strict anaerobes lack superoxide dismutase and catalase
True! Strict anaerobes lack superoxide dismutase and catalase and therefore cannot utilize oxygen which is deadly for them.
Strict anaerobes carry out what 2 forms of energy production ?
They carry out fermentation and anaerobic respiration. Strict anaerobes lack superoxide dismutase and catalase and therefore cannot utilize oxygen which is deadly for them.
What is a Siderophore?
a molecule which binds and transports iron into microorganisms.
What are hemophores
a molecule which binds and transports heme io microorganisms.
- An increase in cell number.
bacterial cell growth
What are the 4 phases of bacterial growth?
- lag phase
- exponential growth phase
- stationary phase
- phase of decline
Does cell division occur during lag
no!
Name 2 characteristics about lag phase
There is no cell division during lag phase (variable length) but there is a marked increase in metabolic activity
There is no cell division during ____ phase but there is a marked increase in metabolic activity.
Lag
you got this
:)
cells are in a state of balanced growth; ratio of RNA
and DNA is proportional to growth rate; cell number doubles with each generation; cells are dividing at a
constant rate. What bacterial growth phase is this ?
Exponential phase
____ phase is characterized by decreased growth rate, accumulation of
waste products, and exhaustion of nutrients.
stationary phase
_____ phase is characterized by cell death.
phase of decline
T/F generation time is the time it takes for 1 cell to divide into 2 cells
True
What are 4 ways that bacteria transport things into the cell
- diffusion (water)
- facilitated diffusion (glycerol)
- active transport (amino acids, lactose)
- group translocation system or PTS (phosphotransferase system).
glycerol is able to enter the cell through which method?
Facilitated diffusion
is ATP required for facilitated diffusion?
No ! It requires a membrane carrier protein but has no energy requirement; molecules
move down a concentration gradient.
T/F active transport requires an energy source
True! Active transport requires a membrane carrier protein and energy source.
Describe binding protein dependent (shock-
sensitive) active transport
- requires :
a) membrane carrier protein
b) binding protein
c) ATP - shocking cells can reduce the efficiency of this
kind of transport in gram-negatives;
Describe ion dependent (shock insensitive) active transport
Requires:
A) a membrane carrier protein
B) energy in the form of PMF
The transport of lactose is an example of ion depended or binding protein dependent shock sensitive active transport?
ion dependent (shock insensitive) active transport
The transport of galactose and maltose is an example of ion depended or binding protein dependent shock sensitive active transport?
binding protein dependent (shock-sensitive) active transport
How does active transport differ from other mechanisms of transport?
Active transport differs from other mechanisms of transport in that molecules are moved
against a concentration gradient, taking substances from areas of low concentration to areas of high
concentration.
killing of all forms of life including spores is called
Sterilization
What sterilization
The killing of all forms of life including spores
killing of vegetative cells is called
disinfection
How does disinfection differ from sterilization ?
sterilization kills spores, disinfection does not
2 sporulating organisms of medical significance
are
Bacillus and Clostridium
look up why Bacillus and Clostridium are of medical significance
idk
T/F killing is exponential
True! not all organisms die at once.
Do all organisms die at once during kiling
no!
What is the most effective method of sterilization ?
Most effective method of sterilization is by autoclaving
List the requirements for proper autoclaving in terms of
temp-
pressure-
time-
121oC
15 lbs. pressure
15-20 minutes
how long does dry heat sterlizaiton take ?
2 hours
When using dry heat sterilization what temp do you use
160 celcius
T/F boiling is a form of sterilization
FALSE! Boiling is not sterilization; does not kill spores.
Formaldehyde is an alkylating agent and targets ______groups on proteins.
Formaldehyde is an alkylating agent and targets functional groups on proteins, i.e., COOH, SH, OH groups.
________ is alkylating agent more effective than ______ as a sporicidal agent
Glutaraldehyde, Formaldehyde
Sterilization of heat-sensitive materials involves use of ______ which is an alkylating agent that
targets the DNA and protein.
Sterilization of heat-sensitive materials involves use of ethylene oxide which is an alkylating agent that
targets the DNA and protein.
ethylene oxide can be used to sterilize what kind of materials?
Heat sensitive materials
If i have a heat-sensitive liquid i.e. protein, drugs, etc. what can I use to sterilize it ?
Filtration – is used to sterilize heat-sensitive liquids, i.e. protein, drugs, etc.
Effectiveness of sterilization in an autoclave is determined using what ?
Effectiveness of sterilization in an autoclave is determined using spore test strips from Bacillus stearothermophilus.
What mechanism of killing by disinfection is described
Disrupt membrane resulting in cell lysis.
detergents - disrupt membrane resulting in cell lysis
What mechanism of killing by disinfection is described:
Oxidizing agents, oxidizing proteins, lipids, carbohydrates – (sporicidal at high concentrations)
halogens – oxidizing agents, oxidizing proteins, lipids, carbohydrates – (sporicidal at high concentrations)
What mechanism of killing by disinfection is described:
cause denaturation of protein and disorganize lipids; heat – denaturation of macromolecules
alcohols - cause denaturation of protein and disorganize lipids; heat – denaturation of macromolecules
What mechanism of killing by disinfection is described:
Causes pyrimidine formation in the DNA which inhibits DNA replication
ultraviolet light - causes pyrimidine formation in the DNA which inhibits DNA replication
What mechanism of killing by disinfection is described:
Targets the cell membrane resulting in lysis and protein denaturation
phenol - targets the cell membrane resulting in lysis and protein denaturation
What mechanism of killing by disinfection is described:
Form mercaptides with sulfhydryl groups of cysteine in proteins
heavy metals (mercury, silver, arsenic) – form mercaptides with sulfhydryl groups of cysteine in proteins.
What mechanism of killing by disinfection is described:
Causes single strand breaks in the DNA
ionizing radiation - causes single strand breaks in the DNA