Microbiology - Exam 1 Material

microbiology

study of living things that cant be seen by naked eye

ecological balance

photosynthesis, decomposition, greenhouse gases

commercial applications

biotechnology; exp: biofuel, detoxify radioactive waste, productions of insulin, antibiotic production

biotechnology

genetically manipulated microorgangisms

Fracastoro

first germ theory proposed; microorganisms are causative agent for disease

spontaneous generation

life arises from dead material

Robert Hooke

used microscope and looked at “cells” of cork tissue; cell theory

Antoni van Leeuwenhock

viewed “animalcules” (living cells) in rainwater and material from his teeth

Francisco Redi

jars and maggots; denied spontaneous generation

Lazzero Spallanzani

run tests for spontaneous generation hypothesis; boiled broth and sealed flasks prevent microbe growth

Ignaz Semmelweis

handwashing/ chlorinated lime solutions to prevent childbed fever

Rudolf Virchow

theory of biogenesis (life arises from life)

Louis Pasteur

repeated Spallanzani’s experiment with swam neck flasks

Pasteur’s findings

microbe are in nonliving matter like air; can be destoryed by heat; air does not create microbes; aseptic technique

aseptic technique

sterile idea discovered by Pasteur

Joseph Lister

“father of modern surgery”; phenol on wounds to reduce infection

Robert Koch

bacteria caused disease; Koch’s postulates

Koch’s postulates

1. same pathogen present

2. pathogen isolated from diseased host

3. pathogen must cause disease when inoculated into healthy animal

4. pathogen isolated from inoculated animal is orginal organism

Angelina Hesse

helped Koch; discovered that agar keeps it’s gel-like properties at warm temperatures and is not consumed by bacteria; led to isolating caustive agent of tuberculosis

Edward Jenner

developed vaccine for small pox; infect people with cowpox and then they never developed smallpox again

chemotherapy

treatment with chemical; chemical has to be more toxic to bacteria than host

Paul Ehrlich

discovered salversan (first chemotherapy drug)

Alexander Flemming

discovered penicilin (first antibiotic)

shapes of bacteria

coccus (low SA), bacillus, spiral (high SA)

strep (arrangement)

chain

staphy (arrangement)

cluster

monomorphic

one shape

pleomorphic

more than one shape; dictated by genome

glycocalyx

coat/layer surrounding bacterial cell, made of polysaccharides

capsule

firmly attached; protects cell from being engulfed; food source

slime layer

loosely attached; trap nutrients; prevent dessication (drying out)

flagella

long appendages for motility

flagella structure

filament (flagellin protein, what protrudes)

hook (attachment)

basal body (anchor and motor)

flagella position

monotrichous: single flagellum

amph: tuft at each pole

lopho: tuft from one pole

peri: all over

flagella motility

rotates like a propellor; propels through “runs” and “tumbles”

axial filament

internal flagella for spirchaetes only (spiral shaped bacteria); allows bacteria to move through host tissue like a drill

fimbriae

polar position or over whole surface; few to 100 per cell; function in adherencep

pili

longer; 1 or 2 per cell; function in transfer of DNA

conjugation

transfer of DNA from one bacteria to another; sex pili; used to aquire antibiotic resistance genes

taxonomy

the science of classification; based on similar characteristics

phylogeny

the study of evolutionary history of a group of organisms (evolutionary relatedness)

Carl Woese

sequenced 16s portion of ribosomal RNA to show evolutionary relatedness

ribosomes (specifically 16s)

what do all organisms have that made it so 16s were used?

low

do 16s have a high or low mutation rate?

low

do we need a high or low number of organisms to get a sequence of 16s?

3 domains of life

bacteria, archaea, eukaryote

bacteria

prokaryotic, cell wall contains peptidoglycan, first amino acid is formylmethionine, has antibiotic sensitivity

archaea

prokaryotic, cell wall varies in composition, first amino acid is methionine, no antibiotic sensitivity

eukaryotes

eukaryotic, cell wall varies, first amino acid is methionine, no antibiotic sensitivity

endosymbiotic theory

eukaryotic cells evolved from prokaryotic cells living inside one another

scientific nomenclature

scientific names; binomial nomenclature (genus and species); name tells you something about organism

reclassification

technological advanced and continued research necessitates a reclassification of some organisms

taxonomic hierarchy

same for all organisms; prokaryotes have a strain designation

stain designation of prokaryotes

rRNA sequence (systemic) and other criteria ie:growth characteristics, morphology, cell arrangement (determinative)

inorganic molecules

any molecules that lack carbon atoms

polar molecules

have a difference in charge across a molecule

polar

water is a good solvent because it is

acid

hydrogen ion donor

base

hydrogen ion acceptor

salt

substance that dissociates in water

organic molecules

any molecule that has carbon in it

carbon

combine in a large number of ways; molecules are complec and form complex function

carbohydrates

sugars and starches

functions of carbohydrates

building blocks of DNA, structural, synthesis, food reserves, energy

structure of carbohydrates

mono, di, and poly saccharides

lipids

fats or triglycerides (non polar)

functions of lipids

structure of cell membrane (phospholipid), energy storage form

structure of lipids

simple → glycerol + fatty acids, saturated vs unsaturated

complex → phospholipids (polar and non polar regions)

proteins

50% dry weight of cell

function of proteins

enzymes, carrier proteins, toxins and bacteriocins, movement, structure, regulation

structure of proteins

building blocks are amino acids, joined by peptide bonds, structure levels

primary level

sequence of amino acids

secondary level

alpha helix and beta pleated sheett

tertiary level

3D structure

quaternary level

2 or more polypeptide chains

nucleic acid

DNA and RNA

function of nucleic acid

deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

structure of nucleic acid

building blocks are nucleotides, 5-carbon sugar, base, phosphate

thymine or uracil

adenine →

guanine

cytosine →

gram positive bacteria

-one cell membrane

-thick cell wall

-cell wall is composed of peptidoglycan and teichoic acids (wall teichoic acid and lipoteichoic acids)

gram negative bacteria

-two cell membranes (inner and outer)

-periplasmic space is packed with proteins and contains the cell wall

inner membrane of gram negative bacteria

contains cardiolipin (functions like chlestrol which promotes fluidity)

outer membrane of gram negative bacteria

outer side is lipopolysaccharide

porins make up a major portion of the proteins

periplasmic space

packed with proteins and contains the cell wall

purple b/c of the thick cell wall

what color does the gram positive bacteria turn during the gram stain test?

pink b/c of a thin cell wall

what color does the gram negative bacteria turn during the gram stain test?

functions of teichoic acids and lipoteichoic acids

-binding of Mg and Ca cations in the cell wall (promotes membrane stability and source of metals)

-negative charge on cell surface

-phosphate reserve

-influences cell permeability

components of lipopolysaccharide

-o-side chain (major antigen)

-core oligosaccharide

-lipid A

it is not a true gram negative because there is no lipopolysaccharide (LPS) on outer membrane

Is Borrelia burgdorferi a gram negative bacteria?

composition of cell wall

peptidoglycan

peptido (peptides)

glycan (sugars)

NAM

is NAG or NAM the site of peptide attachment?

it lacks a cell wall

mycoplasma is neither gram positive or gram negative because

~60

what percent of the cell membrane is proteins?

transport of nutrients and cofactors

what role do membrane proteins serve?

Escherichia coli or EHEC (Ecoli)

what is the disease of the day?

gram negative

is EHEC gram negative or gram positive?

rod and has flagella

what is the shape of EHEC?

it is facultative anaerobe (can with or without)

does EHEC use oxygen for growth?

shiga toxin

-destroys cells which line the large intestine

-escapes into the blood stream and kills erythrocytes

-encoding is Escherichia coli O157:H7