microbio exam 1
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microbio exam 1
intro to micro bio
suggests that animals such as worms can arise spontaneously from non-living materials.
Pasteur and swan-neck flask
organisms from the air settle in the bends and sides of the swan-neck flask. didnt touch the fluid, only when the flask was tipped would it touch bacteria.
1st to challenge spontaneous generation. proved that maggots do not arise from rotten meat
Tyndall and Cohn
Tyndall recognized there were heat-resistant microorganisms. then Cohn discovered (endospores).
using microbes to clean up the enviornment
altering an organisms genetic information by changing its nucleic acid sequence.
diseases that have increased in incidence in the past 2 decades. TSS, SARS, AIDS, mad cow
Antoni van leeuwenhoek
first to observe bacteria. used a lens to look at lake water found amoeba, paramecium and euglena.
-contain membrane bound nucleus
- has internal organelles
: ER, golgi
-maybe single or multicellular
-3 types of eucarya
: Algae, fungi, protozoa
Binarry fission, has flagella
have cell wall (no peptidoglycan)
found in extreme enviornments (hot springs, thermal vents)
rod, sphere and spiral shape
rigid cell wall
binary fission, motile by flagella
kill host cells; all forms of life can be infected by; are intracellualr parasites; DNA or RNA
only in RNA. smaller than viruses. cause plant disease leading to dwarfism.
proteinatious infectious agents. no nucleic acid. neurodegenerative diseases with no cures. bovine, mad cow, kuru
introduced aseptic surgery using phenol
total magnification of light microscope
ability to distinguish between 2 objects.
bending of light rays
inexpensive, uses visible light. views living cells, up to 1,000X magnification. organisms must be stained.
can observe living cells. reflected visible light. can see unstained cells.
good for living cells, and unstained cells. usues bent and direct light.
embeded in resin, slice with a glass knife. beam passes through specimen. cant view living specimens. 10-100,000X magnification.
3d images. coat specimen with gold. non living specimens. shows surface of organism. 10-100,000X magnification.
+ charge. used for staining
-chare. they have no color to them
gram staining steps
1. crystal violet stain.
2. water rinsed, then grams iodine
3.water rinsed. alcohol is added. this would decolorize a G-. and keep color of G+.
4. stain only G- with safranin red
a polymer of NAM and NAG (related to glucose)
endotoxin, not secreted, part of G- cell, G- are some times highly pathogenic.
G+ has teichoic acids made of phosphates. hold sugars and give the cell a - charge
enzyme in body fluids (tears) breaks the bonds of peptidoglycan.
penecillin effects on a cell wall
it is more effective against G-, cuz the outer membrane prevents medication from reching site of action (peptidoglycan layer)
stains a small group of organisms that dont readily take up stains. (mycobacterium). high concentrations of lipids.
not all cells have one. gel material surrounds the cell. made of glycocalyx. protect bact cells from phagocytosis. ex. bacteria on teeth. protect cells from drying out
not all cells make endospores. highly resistant formed by G+ bacteria. not metabolism but can germinate. highly resistant to extreme conditions.
stains and coats thin flagella, increasing diameter so we can see on the microscope.
cluster of cells
selectively permeable. polar head is hydrophilic, and non polar is hydrophobic. phospholipid bilayer. nutrients in a waste out.
surrounds bacterial cell outside cell membrane. gives cell shape. protects from osmotic damage. has peptidoglycan
single, circular double stranded DNA molecule that contains all the genetic information required by a cell
protein synthesis site
some have pili. shorter than flagella
small ridgid protein-bound compartments that provide buoyancy to the cell. gases flow freely into the cell making it less dense.
not all cells make endospores. formed by G+ bacteria. germinate. survive years or centuries. highly resistant to extreme conditions.
one cell divides into 2. and then growth is exponential.
doubling time equation
mixed community. channels for water movement. has nutrients lots of plasmid transfer.
techniques performed to make sure there is no contamination of the work area, worker, and culture.
main goal is to get isolated colonies.
when are metabolites made?
during log phase
a product of a chemical reaction in a cell and compounds required for growth, waste materials. flavoring agents and food supplements.
-5 to 15C ex: glacier, mountain river.
20-30C refridgerator, air conditioner
25-45C pathogens, food on the counter
45-70C hot springs, compost pile
70-110C volcano, thermal vent in ocean
no replication in the presence of oxygen, oxygen may cause death. grow at bottom of the tube.
grow better with oxygen (more ATP). switch from aerobic to fermentation if no oxygen present. grows more towards the top but generally equally spread.
absolute requirement for oxygen. bacteria need it for ATP production. grows more towards the top.
requires small amount of oxygen, too much inhibits growth. grows a little bit down from the top.
can grow with oxygen, but do not use it to transform energy. neither anaerobic or aerobic. growth they are evenly spread out.
most bacteria 6.5-7.5= neutrophiles
acidophiles below 5.5
very few grow under 4
water loss. if a solute is higher on the outside of a cell, water will move out and the cells membrane shrinks
movement of water across a membrane from dilute solution to a more concentrated solution.
C, O, H, N, Su, P, K, Mg, Ca, Fe
cobalt, zinc, copper, molybdenum, and maganese
uses sunlight and CO2 as carbon source
uses sunlight energy and organic carbon (not CO2).
uses inorganic carbon for energy and CO2 as carbon
uses organic carbon compounds for energy and carbon source. eukaryotes, humans and other animals.
contains variety of ingredients. no exact chemical formula. EX. nutrient agar.
precise amounts, replicate it exactly every time, pure. we dont use this because it is too expensive.
inhibits the growth of some organisms while selecting for others. Ex. EMB
color change. differentiated between different organisms growing on the same plate.
removes ALL microbes. by filtration, heat, chemicals, and irradiation
eliminates most pathogens. disinfectants are used on surfaces,and antiseptics are used on the skin
breif heat treatment used to reduce organisms that cause food spoilage. ex. milk, juice, water
what would influence you in selecting a antimicrobial procedure?
1. type of microbe
.2 number of microbes initially present
3. enviornmental conditions
4. potential risk of an infection
5. composition of the item
destroying microbes with heat
its most useful for microbial control fast, safe, reliable, inexpensive. heat sterilizes and disinfects. 121c for 15 mins.
destroying microbes with filtration
remove microbes from fluids and air. Air- by HEPA filters.
destroying microbes with raidation
causes damage to the DNA and potentially to plasma membrane. used to sterilize materials that arent heat resistant. Ex. x-rays, gamma rays.
destroying microbes with pressure
used in pasteurization of foods. not high temp, but pressue. denatures the proteins.
function of autoclave?
device that uses steam under pressure steralize materials that are stable to heat and moisture.
factors that would influence you on selecting a certain antimicrobial chemical.
low temperature, reducing available water, adding salt or sugar, drying food.
commonly used as an antiseptic gel and disinfectant
inactivates proteins and DNA
used in anitseptics cuz of low toxicity. ex: mouth wash
germicide: ethylene oxide
a gas that destroys microbes including endospores and viruses
chlorine is used as a disinfectant and iodine kills vegetative cells only.
hydrogen peroxide. like using it on a cut.
ex: lysol. destroys the plasma membrans and denatures proteins. ex: soaps lotions.
non-toxic. the quats positive charge attracts to the negatice charge of the cell surface.
silver interferes with enzymes and proteins. ex: cream for burns. its an oxidizer "attacks foreign material.
utilizes energy stored in ATP to synthesize and assemble building blocks of macromollecules that make up the cell
harvest energy released during the breakdown of compounds such as glucose, using it to synthesize ATP
energy of all cells
substrate level phosphorylation
synthesis of ATP using the energy released in exergonic chemical reaction