Microbiology - Module 1-2

Fluid Mosaic Model

Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer

Transmission Electron Microscope (TEM)

Thin-sectioning used to view internal details, but the process can distort cells transmits beam of electrons through specimen

Scanning Electron Microscope (SEM)

Used to observe surface details Surface coated with thin film of metal Beam of electrons is scanned over surface Electrons released from specimen are observed Yields 3-D effect

Koch's Postulates

When you isolate the microorganism, it must be grown in a lab (weakest postulate) Once you grow the microorganism, you must inject it into a living animal, and must show that it produces those symptoms in that living animal

Proton Motive Force

a proton is moved into a cell, either bringing another molecule with it, or causing another molecule to be pushed out of the cell

Cytoplasmic Membrane

defines the cell boundary selectively permeable hydrophobic tails and hydrophillic heads O2, CO2, N2, small hydrophobic molecules, and water can pass through it

Golden Age of Microbiology: Louis Pasteur (Pasteurization)

demonstrated that bacteria that caused spoilage of wine could be killed by heat that was not hot enough to evaporate the alcohol in wine heating a food item to a high temperature and cooling it rapidly - kills bacteria that can cause spoilage and allows food to be stored for a longer period of time

Penicillin and Impact on Peptidoglycan

interferes with peptidoglycan synthesis interferes with protein crosslinking usually more effective against gram-pos than gram-neg because the outer membrane of gram-neg blocks access bacteriocidal

coccobacillus

intermediate between coccus and baccillus

Flagella

involved in motility spin-like propellers move cell 3 parts: Basal Body, Hook, and Filament

Biogenesis

living things come from other living things

Prokaryotic Morphology: Spirochete

long, spiral-shaped cell w/ a flexible cell wall and unique mechanism of motility

Microbiology: Human Perspective

microbes have benefit for us -normal microbiota, group of organisms that colonize the body surfaces but do not usually cause disease -help degrade food, combat disease-causing microbes, promote immune system

Electron Microscope

microscope that forms an image by focusing beams of electrons onto a specimen uses electromagnetic lenses can magnify more than 100,000x

Active Transport

movement against gradient (low to high) uses proton motive force and ATP

Viruses

nucleic acid (DNA or RNA) packaged in protein coat must infect living cells, hosts multiply using host machinery and host nutrients - obligate intracellular parasites because inactive outside of hosts NOT ALIVE

Prions

only protein, no DNA or RNA misfolded forms of normal cellular proteins found in the brain that cause normal ones to unfold cause several neurodegenerative diseases in humans and animals (Ex: mad cow disease) resistant to standard sterilization procedures

Pleomorphic

organisms that are variable in shape bacteria that characteristically vary in their shape

Diplobacilli

pairs of bacilli

Diplococcus

pairs of round cells

Gram-Positive Cell Wall

thick peptidoglycan layer have teichoic acid and lipoteichoic acid better at preventing water loss

Gram-Negative Cell Wall

thin peptidoglycan layer has unique outer membrane on outside that has lipopolysaccharides

Carl Woese

took bacteria domain and observed RNA sequences; realized that you could split them into two distinct domains - bacteria and archaea

Chemotherapy

treatment with chemicals chemotherapeutic agents can be synthetic drugs or antibiotics

Light Microscope

uses visible light and series of lenses to magnify objects modern light microscope (compound microscope) has multiple magnifying lenses can magnify 1000x

Eucarya: Helminths

worms

Lipopolysaccharide: O Anitgen

Can be used to identify bacterial species or strains

Arrangements: Clusters

Cells divide in several planes at random

Osmosis

Diffusion of water across selectively permeable membrane

Nomenclature

Genus Species Genus - italicized or underlined, capitalized Species - italicized or underlined, not capitalized

Spontaneous Generation

Hypothesis stating that life could arise from nonliving matter.

Simple Diffusion

Movement of molecules from high to low concentration Speed depends on concentration

Lacking a Cell Wall

Mycoplasma have extremely variable shape (pleomorphic") because they lack peptidoglycan penicillin and lysozyme do not affect these bacteria

Domains

Bacteria, Archaea, Eukarya

Sarcina

cubical packets of 8 cocci

Prokaryotic Morphology: Spirillum

curved rod long enough to form spirals thicker than spirochete

Prokaryotic Morphology: Rod

cylindrical

Applications of Microbiology: Food Production

- baking bread using yeast - fermentation of grains to make beer - fermentation of milk - pickled foods

Applications of Microbiology: Biodegradation

- degrade PCBs, DDT, trichloroethylene - help clean oil spills - bioremediation, using microorganisms to hasten decay of pollutants

What are emerging diseases caused by?

- evolution of infectious agents previously unable to infect humans - resistance to antimicrobial medications - increased travel and immigration - changes in population

John Needham

- experiment showed that microorganisms did arise spontaneously -boiled uncovered flasks of broth and then corked it --> gave rise to microorganisms - thought this proved broth gave rise to bacteria

John Tyndall

- helped support Pasteur's experiments due to skepticism that Pasteur's experiments could be replicated - found that some microorganisms can easily be killed by boiling while others can be heat resistant - experiments with hay showed that hat had some heat-resistant forms of microorganisms Later Ferdinand Cohn discovered endospores

Lazzaro Spallanzani

- refuted Needham's experiments and refuted idea of spontaneous generation showed that a sealed flask of meat broth sterilized by boiling (Covered during boiling) failed to grow microbes -heated for longer and covered while boiling / potentially sealed by melting glass necks - although refuted spontaneous generation, some people argued that the heating process destroyed a vital force in air necessary for spontaneous generation

Hypertonic

A cell is hypertonic when there is more solute on the outside of cell membrane than inside more solute on outside = less water on outside water will flow out of the cell and cause the cell to shrivel

Hypotonic

A cell is hypotonic when there is less solute on the outside of the cell membrane than inside less solute on outside = more water on outside water will flow into the cell and cause it to swell

Prokaryotic Morphology: Coccus

A spherical bacterium.

Peptidoglycan

Alternating series of subunits form the glycan chains NAM and NAG alternate then, a tetrapeptide chain (String of 4 amino acids) is what links the glycan chains

Streptobacilli

Bacilli arranged in chains, as the cells divide in one plane

Lipopolysaccharide: Lipid A

acts as a pyrogen (fever-generating) immune system recognizes it

Germ Theory of Disease: Ignaz Semmelweis

advocated hand washing to prevent transmission of puerperal fever (childbirth fever) from one OB patient to another

Robert Hooke

also credited with discovery of microscope described "microscopical mushroom" used word "cells" to describe cork, a type of bark

Bacteristatic

an antibody that does not kill, but slows down the growth rate of the bacteria want to use bacteristatic against gram-negative bacteria

Bactericidal

an antibody that will kill the bacteria in the process of killing the bacteria, the bacteria will be broken open and it will liberate the inner components - if you used bactericidal on gram-negative bacteria, it could liberate too many endotoxins and lead to endotoxic shock

Flagella: Basal Body

anchors the structure to the cell wall and cytoplasmic membrane

Bacillus Arrangement Special Considerations

bacillus cannot make packets or staphylo arrangements! if you see a bunch of bacillus grouped together, they are simply called a group of bacillus

Applications of Microbiology: Commercial Product Production

bacteria can be used to synthesized commercially valuable products such as amino acids, antibiotics, ethanol, hydrogen gas, etc.

Eucarya: Fungi

can be single-celled or multicellular get energy from degradation or organic materials cell wall contains chitin - polysaccharide, brittle material that makes up shells of insects, shellfish

Atomic Force Microscope

can produce images of individual atoms on a surface gives detailed images of surfaces resolving power much greater than that of EM

Arrangements: Packets

cells divide in 2 or more planes perpendicular to one another

Arrangements: Chains

cells divide in one plane

Antibiotic

chemicals produced by bacteria and fungi that inhibit or kill other microbes

Streptococcus

cocci in a long chain

Bacterial Cell Wall

composed of peptidodglycan - protein/carbohydrate complex peptidoglycan layers can distinguish between gram positive and gram negative

Francesco Redi

did meat/maggot experiment - people thought worms arose from dead meat --> supports idea of spontaneous generation - showed that when meat was covered with gauze, there were no flies (flies could not deposit their eggs) - when meat was uncovered, flies would deposit their eggs - when meat was tightyly sealed in container, flies did not attract and maggots did not form - when meat was covered with gauze, flies attracted but no maggots formed experiment refuted idea of spontaneous generation

Contrast

difference in color intensity between object and background

Slime Layer

diffuse, irregular allow attachment to surface (forming biofilms) most are made of glycocalyx - capsule or slime is determined by how this secretion is arranged

Germ Theory of Disease: Louis Pasteur (silkworm)

discovered that another serious disease of silkworms was caused by a microscopic organism now known as Nosema bombycis

Golden Age of Microbiology: Alexander Fleming

discovered the first antibiotic noticed that the fungus Penicillium made a chemical that killed the bacterium S. aureus

Capsule

distinct, gelatinous layer protect against phagocytosis help evade immune system most are made of glycocalyx - capsule or slime is determined by how this secretion is arranged

Light Microscope: Condenser Lens

does not magnify only focuses light on the specimen

Old Friend's Hypothesis

early exposure helps the immune system learn to distinguish "friendly" microbes from those that can cause severe disease

Lysozyme and Impact on Peptidoglycan

enzyme found in tears, saliva, other bodily fluids destroys structural integrity of peptidoglycan molecule interferes with glycosidic bonds between NAG and NAM especially effective against Gram-Positive since there is no outer membrane present

Stanley Miller

experimented to see if the gases hypothesized to exist on early earth could really create organic compounds. He filled a flask with all of the proposed gases early earth had, heated it, and gave it occasional electric charges, and after a week, he discovered amino acids had formed in the mixture.

Light Microscope: Occular Lens

eyepiece lens close to the eye

Louis Pasteur

father of modern microbiology - demonstrated that air contains microorganisms - filtered air through cotton plug to trap them - demonstrated that sterile broths in swan-necked flasks remained sterile even when open to air (they settled in neck, never reaching broth, but when the flask was tipped and organisms could reach water, they contaminated water) - ended arguments of unheated air or broths having vital force fo life credited with theory of biogenesis

Cyanobacteria

first organism that can carry out photosynthesis and produce O2

Antony van Leeuwenhoek

first person to observe and describe microorganisms accurately "animalcules" made simple microscope - started science of microbiology

Flagella: Hook

flexible, curved segment that extends out from the Basal Body, connecting it to the Filament

Facilitated Diffusion

form of passive transport movement of molecules down concentration gradient; no energy required

Staphylococcus

grape like clusters of cocci

Teichoic Acid

holds the layers of peptidoglycan together

Resolution

how much detail can be seen in the specimen measure of the ability to distinguish two objects that are very close together minimum distance between two points at which they are still separate objects

Golden Age of Microbiology: Edward Jenner

inoculated a child with the cowpox virus, and showed that the child was then protected from smallpox smallpox evolved from cowpox - smallpox spike proteins have some of the original spike proteins of cowpox Jenner noticed that women who milked cows came down with cowpox, but never smallpox - same antibodies that neutralize cowpox, also bind to the spike proteins of smallpox

Lipopolysaccharide

phospholipid layer with sugars 3 parts: O-Antigen, core oligosaccharide, and lipid A Many of these sugars act as antigens and allow us to differentiate strains of bacteria. Plays an important role in endotoxic shock - LPS is an endotoxin and too much leads to mass inflammatory response, dilation of vessels, drop in BP, etc. medically important - alerts immune system of invasion by gram-neg, small levels of LPS cause appropriate immune response to get rid of bacteria, etc.

Archaea

prokaryotes similar shape and size to Bacteria rigid cell walls LACK peptidoglycan multiply via binary fission can move using flagella many are extremophiles - extreme conditions

Golden Age of Microbiology: Robert Koch

proved that a bacterium causes anthrax; Baccilus anthracis developed experimental steps that could be used to prove that a specific microbe causes a specific disease - Koch's Postulates

Palisades

resembles a picket fence and arranged in angular patterns wall-like arrangement

Lipoteichoic Acid

runs through the peptidoglycan layers and anchors it to the plasma membrane

Light Microscope: Objective Lens

series of lens right above the object being viewed

Prokaryotic Morphology: Vibrio

short, curved rod looks like a comma

Germ Theory of Disease: Agostino Bassi

showed that a silkworm disease was caused by a fungus preceded Louis Pasteur in the discovery that microorganisms can be the cause of disease

Viroids

simpler than viruses require host cell for replication - obligate intracellular agents consist of single, short piece of RNA no protective protein coat cause plant diseases, but no evidence of causing human diseases

Eucarya: Protozoa

single-celled complex, larger than prokaryotes can live in both aquatic and terrestrial environments do not have rigid cell wall (unlike algae and fungi) motile (use flagella, cillia, or pseudopods) ingest organic compounts

Eucarya: Algae

single-celled or multicellular photosynthetic and contain chloroplasts mostly live in water rigid cell walls of cellulose many have flagella (cell walls and flagella distinct from those of prokaryotes

Bacteria

single-celled prokaryotes no membrane-bound nucleus, instead has nucleoid region have specific shapes (rods, spiral, etc.) has rigid cell wall that contains peptidoglycan multiple via binary fission can move using flagella

Prokaryotic Cells SA:V

smaller size gives high surface area to low volume if cell grows beyond certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume allows quick uptake of nutrients and excretion of wastes allows rapid growth (eukaryotic cells are able to be larger and more complex because they have organelles that help with efficiency)

Size in Microbial World

smallest --> largest atom - small molecules - lipids, proteins - ribosomes - viruses - mitochondria - most bacteria - nucleus - most eukaryotic cells

Periplasmic Space

space between outer membrane and cytoplasmic membrane that is filled with gel-like periplasm

Golden Age of Microbiology: Paul Erlich

speculated about a "magic bullet" that could destroy a pathogen without harming the host developed a synthetic arsenic drug, salvarsan, to treat syphilis

Golden Age of Microbiology

started after the theory of spontaneous generation was disproved time period where most pathogenic bacteria were identified work on viruses began discovery of antibiotics