Microbiology EXAM 1

what are the morphologies of bacterial cells

what is the morphology of coccus

what is the morphology of bacillus

what is the morphology of coccobacillus

vibrio look like?

spirillium look like

pleomorphic shapes are

extracellular layer that holds bacterial cells together after cell division

what is the good news of an organism that forms groups?

what is the bad news of an organism that forms groups?

allows bacteria to move from on place to another.

alls cells to swim freely through an aquesous habitat.

what are the three subtypes of flagella ?

what is monotrichous

what is lophotricphous

what is amphitrichous

what is peritrchious flagella?

flagella can detect and move to chemical signals this type of behavior is called
ex: toward food and away from stimulus such as chemical toxins

movement of a cell in the direction of a favorable chemicial stimuulus/ attractant (usually a nutrient)

movement away from a repellent (potientially harmful) compound.

in chemotaxis for flagella when it is swimming toward attractant the flagella will

with flagella, if the bacteria is moving toward a repellent the flagella will

swim toward/away from light

swim toward/away from oxygen supply

moving toward/away from magnetic field. coordinates movement in response to magnetic fields. ex: orient to earth's magnetic field

small, bristlelike fibers emerging from the surface of many bacterial cells.
- most contain protein.
- tendency to stick to each other/ and surfaces.

elongated, rigid tubular structure made of special protein.
-only in gram-negative where they are utilized in "mating"

mating process between cells.
involves partial transfer of DNA of one cell to another.

they may be responsible for the mutual clinging of cells that leads to biofilsm and other thick aggregates of cells on the surface of liquids and for the microbial colonization of inanimate solids such as rock and glass

some pathogens can colonize and infect host tissues b/c of tight adhesion between their what?

in the conjugation of pilus. a pilus from a donor cell unites with a recipent cell thereby providing...

inner most part of a bacterial cell

forms thick layer over inner cell membrane. where cell walls gain their stability and strength from

protects the cell from osmotic shock

definition: a network of polysaccharide chains cross-linked by short peptides hat from the rigid part of bacterial cell walls

a peptide inter-bridge between the Diaminopimelic Acid of one glycana chain and the D-Alanine of another. the composition of this inter-bridge varies between species

the tetrapeptides are joined directly

examples: rubber cement, weak, soluble

ex: rubber car tire, strong, tough, insoluble, lasts longer

definition: think homogeneous sheath of peptidoglycan ranging from 20 to 80nm in thickness. also contains tightly bound acidic polysaccharides including: teichoic acid directly attached to peptidoglycan and lipoteichoic acid

a polymer of ribitol or glycerol and phosphate embedded in peptidoglycan sheath. project outward from peptidoglycan layer. immunogenic

attached to the lipids in the plasma membrane.
project inward from peptidoglycan layer to cytoplasmic membrane- anchor.

composed of an outer membrane and thinner shell of peptidoglycan. contains specialized types of LPS and lipoproteins.
no peptide inter-bridge

composed of lipid molecules bound to polysaccharides. the lipids form the matrix of the top laye of the OM and the polysaccharides strand project from the lipid surface.

resistant to certain antibiotics

inserted in the upper layer of the outer membrane. they have some regulatory control over molecules entering and leaving the cell.

many qualities of the selective permeability of gram-negative bacteria to bile, disinfectants, and drugs are due to the

just underneath the outer membrane.
above and below peptidoglycan
important reaction site for a large and varied pool of substances that enter and leave the cell.
houses secreted degradative enzymes (pathology)

disrupts cross-linking between glycan molecules (makes the pepto layer weak)
more effective against gram+ b/c its excluded by prions in gram-

largerly composed of mycolic acid making them appear waxy and more resistant to chemicas, dehydration, antibiotics (pathology)

bacteria without a cell wall
containssterols that make it resistant to lysis
found in may habitats such as plants, soils and animals

form or shape. tendency for cells of same species to vary in some extent in shape in size.
mycoplasmas are this

contain peptidoglycan and stain gram-positive, but the bulk of their cell wall is composed of unique types of lipids.
ex: TB

underneath the cell wall
regulates transport into/out of the cell
flexible sheet molded completely around the cytoplasm
lipid bilayer with proteins emedded to varying degrees

polar head oriented toward the outside
nonpolar head towad the center of the membrane
embedded at numerous sites in this bilayer of various-size globular proteins

freely permeable to water, dissolves gases, and small hydrophobic molecules by simple diffusion

too big to go through cells
ex: glucose and amino acids

how do bacteria acquire most of their raw materials?

what are the types of transport proteins?

transport of two substances in the same direction
ex: sugars

transport of 2 substances in opposite directions
ex: anitbiotics

transports one substance in one direction (either in or out)
ex: cations, potassium, calcium

clever (esp. for bacteria)
the substance is chemically altered during transport (phosphotranserase system)
ex: glucose and other sugars
the cell can soak up all the glucose by converting into glucose-phosphate

how do bacteria sense and respond to their environment?

transduce chemical signals from outside the cell to inside the cell

a single, circular, supercoiled, double stranded DNA molecule.
replicates only when the cell divides

what are the types of bacterial chromosome

where one gene goes so do all the other (little variation)

easier to replicate than linear (humans have linear)

like, ours and replicates like ours

inside the bacterial cell
the molecular machine that assembles amino acids into proteins
comprised of 54 proteins and 3 RNAs
target of many antibiotics

withstands hostile conditions and faciliate survival.
dormant bodies produced by bacteria Bacillus, and Clostridium.
two-phase life cycle taht shifts between a vegative cell and an endospore
exists in an inert, resting condition that is capable of high resistance and very long-term survival.

the time required for a complete fission of cycle. from parent cell to 2 new cells is called

the period between an individuals's birth and the time of producing offspring. in bacteria each new fission cycle increases the population by a factor of 2, or doubles it

a measure of the growth rate of an organism
compared with the growth rates of most other living things, bacteria are notoriously rapid.
average for bacteria is 30-60

N_t

N₀

n

how do you get n?

what do you get when nutrients are limited?

what are the stages of growth curve?

period of adjustment
no increase in cell number
cells dont divide
flat period on the graph when the population appears not to be growing or is growing at less than the exponential rate

cell number doubles every generation
(caused by unlimited nutrients)

no net incrase/decrease in cell number
(cell division = cell dealths)
(caused by depleted nutrients/build-up of toxic by products)

net decreased in cell number
caused by prolonged stationary phase

what are major factors that control bacterial cell growth?

what is the temperatuure requirement for psychrophiles (many pseudomonas) ?

what are the temperature requirements for mesophiles (e. coli and all human pathogens) ?

what are the temperature requirements for thermophiles ( lactobacillus delbruekii- yogurt)?

what are the temperature requirements for hyperthermophiles (pyrolobus fumarimii -ocean vents)?

require the level of oxygen normally present in air

require the absence of oxygen

can grow in the presence OR absence of oxygen but grow faster with oxygen

require reduced levels of oxygen

grow equally well in the presence as in the absence of oxygen.
(they dont use oxygen at all so doesnt matter)

types of energy sources

derives its energy from the sun (plants)

derives its energy from organic compounds (us, glucose, fatty acids)

derives its energy from inorganic sources (rocks)

what are the carbon sources

derives carbon from CO₂

derives carbon from organic compounds (sugars/amino acids/fatty acids)

what are the combinations of carbon sources

derives energy from the sun AND carbon from CO₂

derives its eergy from organic compounds AND its carbon from organic compounds

derives its energy from the sun AND its carbon from organic compounds

ph sources are

grow best from pH 5 to pH 8 (most bacteria)

grow best pH 5 (heliobacter pylori)

grow best above pH 8 (Bacillius alcalophiles) few but not many

what is a water availability source?

tolerant to relatively high (10%) salt concentrations (staphylococcus some Archae)

what are factors to consider in control?

list the types of organisms we learned, from hardest to control to easiest.

explain the number or organisms present as a factor to consider in control

explain the environmental conditions to consider in control?

what is the D value graph

what are physical methods for reducing bacterial populations?

200 degrees C for 1.5 hours to for sterile (wire loop)

121 degrees C for 15 mins for sterile

dehydrate vegetative cells

denature proteins disrupt the 3 d structure

mutagenic

oxidizing agents (chemically alter proteins)

react with sulfhydral groups (Hg)

ozone (chemical control of bacterial populations)

peroxides (chemical control of bacterial populations)

destroy cell membrane/proteins (chloraspetic)

quatemary ammonium compounds (quats)
(chemical control of bacterial populations)

types of radiation and bacterial populations

what do gamma rays do

what are ultraviolet rays

what do x-rays do

prevent population from getting bigger

kill bacteria and decrase the size of the population

classified based on their chemical structure, mechanism of action, and biological source

Beta-lactams
effective against?
mechanism?
examples?

Semi-synthetic penicillin
examples
effective against
mechanism

Clavulanic Acid
examples
effective against
mechanism

Aminoglycosides
mech?

glycopeptides
examples
effective against
mechanism?

polyeptides
example?
effective against/spectrum?
mechanism?

Rifamycins
example?
effective against/spectrum?
mechanism?

polyenes
example:
spectrum/effective against?
mechanism?