Microbiology Ch 1 - Ch 3
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Microbiology Ch 1 - Ch 3
Unit 1- chapter 1 and Chapter 3
Robert Hooke contribution?
1665 observed cork cells using compound lens.
termed word "cells" began "cell theory"
Antony Van Leeuwenhoek contribution?
first observations of living cells taken from his own body.
first microscope using magnifying lens
some forms of life could arise spontaneously from nonliving matter
spontaneous generation myths
fleas from hair
flies from fresh and rotting fruit
locusts from green leaves
raccoons from hollow tree trunks
termites from rotten wood
eels from slimy mud at the bottome of bodies of water
mosquitoes from stagnant pond water
who proved existance of microorganisms?
what experiment did Pasteur use to prove microorganisms exist?
filtered air through cotton plug showing that filterable particles cause contamination of sterile broths.
what steps were involved in pasteur's experiment?
trapped air escapes from open end flask (sterile broth)
bacteria/dust from air settle in bend of flasks
broth sterile indefinately
flask tilted so sterile broth makes contact with contaminated bacteria/dust from air
bacteria multiplies in broth
why was Pasteur lucky he used animal broth? how would his experiment have been different?
if he used vegetable broth or soil broth there would have been endospores present and that has a bacterial state that is very hard to kill
study of microorganisms
what techniques are utilized in microbiology?
pure culture technique
microscopic observation of whole organism's
who is Linnaeus and what what his contribution?
establish system of scientific nomenclature, where each organism has 2 names, the genus and species.
genus = first word, capitalized
species=italicized, lower case
4 domains for classifying microorganism?
4. Nucleocytoplasmic Large DNA Virus (NCLDV)
types of bacteria
cyanobacteria (blue green algae)
what type of nutrients do bacteria have?
1. chemotrophs- use chemical for energy
2. phototrophs- use light for energy
examples of bacterial diseases?
durable state of bacteria?
some form endospores
how to tell how many clusters or numbers of bacteria?
(strepto)- row or line
what does diplocoques mean?
2 sphere shaped bacteria
what does streptocoques mean ?
line or row of sphere shaped bacteria
what does staphylocoques mean?
cluster of sphere shaped bacteria
what color is cyanobacteria?
description of Archaea?
live in extreme environments
none are known to cause disease
types of archaea?
methanogens- produce methane as waste product of respiration
extreme halophiles- extreme salty environment
extreme thermophiles-extreme hot, sulfurous environment
basic qualities of bacteria
simple single cell (unicellular),
genetic material not enclosed in nuclear membrane,
peptidoglycan cell walls
reproduce by binary fusion
appear in various shapes:
* Bacillus- rod like
*Coccus- spherical or ovoid
*Spiral- corkscrew or curved
qualities of fungi
chitin cell wall
use organic chemical for energy
which fungi are unicellular/multicellular?
what is hyphae?
filaments that consist of masses of mycelia in molds adn mushrooms
qualaties of protozoa
slime molds, flagellates and ciliates
absorb/ingest organic chemical for energy
some form durable cysts
examples of protozoa diseases?
qualaties of helminths?
flatworms, roundworms, nematodes
some are multicellular animal parasites
microscopic stages in life cycle
examples of diseases of helminth?
qualities of algae?
brown, red, green
in larvae stage are swimmers
cellulose cell walls
uses photosynthesis for energy
disease of algae?
some poisoning associated with unicellular types
qualaties of virus?
not cells but some have lipid membranes and require cells to reproduce
acellular, obligate intracellular parasites
cant cure only treat s/s
diseases of virus?
what are prions?
consist of DNA, RNA, protiens
disease from prions?
ALL ARE FATAL
How do microbes influence ecology?
produce energy to ecosystem
make nutrients avail from inorganic sources
decomposers-liberate nutrients from no longer living sources
form symcioses (mycorrhizal fungi assoc with plant root, found in legume nodules)
serve as endosymbionts (chloroplast, mitochondria)
how do microbes influence industry?
fermentation products -cheese, hyogurt, bread, pickles
biotech- recombinant products such as insulin/vaccines
bioremediation- microbes used at max. levels to degrade other microbes
Historians and thier contributions to microbes
1796- Edward Jenner -
innoculated person w/ cowpox and they were then protected from small pox (immune) and coined term
1860- Joseph LIster
- inspired by Pasteur, used chem disinfect to prvent surgical wound infect.
1876- Robert Koch
- proof that bateria causes anthrax and proved experimental steps to prove specific microbe causes specific disease
(germ theory of disease
what is normal microbiota?
produce growth factors such as folic acid and vit K
hygeine hypothesis- we are too clean so immune system out of whack.
ability for body to ward off disease
why does disease occur?
when pathogen overcomes host's resistance
conversion of units of measurement?
1 um = 10 ^ -6 = 10 ^ -3 mm
1 nm= 10 ^ -9 = 10 ^ -6 mm
1000 nm = 1 um
0.001 um = 1 nm
images from objective lens (eye) magnifies through second lens (object)
total magnification = objective lens X ocular lens
lenses to distinguish two points
shorter wavelengths of light provide greater resolution
what increases resolution?
immersion oil d/t light not bouncing or bending
what is refractive index
light bending ability of medium
why is immersion oil used for better resolution?
keep light from bending so it doesnt miss the small high magnification lens
dark objects visible against bright background
light is reflected off specimen adn doesnt enter objective lens
light objects visible against dark background
light reflected off specimen enter objective lens
what microscope we use in lab?
phase contrast microscopy
accentuates diffractrion of light that passes through specimen
uses UV light
fluorescent substance absorb UV light and emit visible light
cells may be staind with fluorescent dye
uses fluorochromes and laser
laser illuminates each plane in specimen to
produce 3 D image
what are the 2 types of highest resolution microcopy?
electron Microscopy- uses electrons (shorter wavelength then light)
Scanning Probe and Atomic Force Microscopy (creates image with similar resolution but does not use electrons)
what is transmission electron microscope?
electron microscope that transmits electrons through substance
specimen may be stain with heavy metal salt
sliced and very thin sections
what is scanning electric microscopy?
electron microscope where electron gun fires beam of electrons
electrons bounce off surface of specimen
3 D image
scanning probe microscopy
uses metal probe to scan specimen
resolution 1/100 of atom
atomic force microscopy
uses metal and diamond probe inserted into specimen
how to prepare specimen?
thin film of soln smeared on slide
smear is "fixed" or attached to slide (kills microbes- overheating can distort shape)
purpose of staining
definition of contrast
results from differences in index of refraction between specimen and background
or results with difference in index of refraction within specimen and number of visible colors in specimen
what colors are highest contrast?
black / white
what increases contrast?
black / white color
closing the iris diaphragm
use of a single basic (alkaline) dye
mordant may be used to hold stain or coat specimen
what is mordant?
coating used to hold stain on specimen
makes specimen appear larger
what does gram stain classify?
a) gram positive
b) gram negative
what can kill gram positive bacteria
penicillin and detergents
gram negative bacteria and antibiotics
gram negative bacteria more resistant to antibiotic
color changes with gram positive/ gram negative stain?
gram positive will be stay purple color
gram negative will stain red
how to do a gram stain?
add alkaline crystal violet (simple stain)
add iodine (mordant - attach to crystal violet) all cells purple
decolorize with alcohol (crytal violet washes out gram negative cells)
counter stain with safranin
gram positive remains purple
gram negative counterstains red
acid fast staining
cells that retain basic stain in presence of acid- alcohol
what happens to non acid fast cells?
loose basic stain when rinsed with alcohol and are usually counterstained with different basic stain.
what stain is used to look for pathogenic TB?
acid fast staining
usefull to visualize capsule around bacteria
stains background dark (doesnt stain bacteris only background)
less distortion of cells then other special stains
no heat used
if halo around bacteria?
bacteria is sticky if it has a halo around it and wants to stick. if no halo, then not sticky. If it is sticky then it has a sugar coating around capsule
domains of eukarya?
common myths to spontaneous generation
Toads, snakes and mice being born of moist soil
Flies emerging from manure
Maggots (larvae of flies) could arise from decaying corpses.
Snakes from horse hairs in stagnant water
Mice from grain and cheese wrapped in a sweater
Maggots from rotting meat
Fleas from hair
Mosquitoes from stagnant pond water
Eels from slimy mud at the bottom of bodies of water
Locusts from green leaves
Termites from rotten wood
Raccoons from hollow tree trunks
who was Francesco Redi and what did he contribute to microbiology?
1668 maggots did not arise spontaneously from decaying meat