MICR midterm

spontaneous generation theory

living creatures could arise from non living matter

Bubonic plague

Yersinia pestis; certain death, infection in lymph nodes

Smallpox

Variola virus; airborne, contagious

Cholera

Vibrio Cholerae; small intestine infection

miasma theory

theory that diseases were caused by ‘bad air’

germ theory

some diseases are caused by microorganisms; contributors: john snow, louis pasteur

louis pasteur

microbes fail to appear in swan neck flasks, first artificial vaccine against anthrax

robert koch

proved tb is caused by microorganism, pure culture technique

kochs postulates

1. microbe is found in all cases of the disease

2. isolated from host and grown in pure culture

3. introduced into healthy organism, same disease occurs

4. same strain of microorganism is obtained from newly diseased host

edward jenner

smallpox vaccine, using cowpox blisters

joseph lister

sterilization

alexander fleming

discovery of antibiotics; penecillin, Penicillium notam inhibits growth of Staphlococcus, Penicillium rubens more effective strain

antibacterial drug targets

regions of cell that are impacted by antibiotics;

antibacterial drug resistance

evolved mechanisms to work despite antibiotics; eg. blocked penetration, efflux pump

e. coli

Escherichia coli

3 domains of life

bacteria, archaea and eukarya

kids play catch over farmer greens shed

Kingdom, Phylum, Class, order, Family, Genus, species

bacterial cell wall

peptidoglycan; sugars and amino acids

coccus

round

bacillus

rod shaped

vibrio

curved rod shaped

coccobacillus

round, rod shaped

spirillum

wavy spiral shape

spirochete

tightly spiral shaped

archaeal cell wall

pseudopeptidoglycan

protists

not plants, animals or fungi; Algae or Protozoa

algae cell wall

cellulose

fungi cell wall

chitin

mould

Penicillium hyphae

viruses consist of:

proteins and genetic material (acellular)

human eye can see:

1mm, 10^-3 m

light microscopy can see:

10^-3→10^-6m (1mm to 1 micrometer)

scanning electron microscopy can see:

1mm-10nm (10^-3→10^-8m)

transmission electron microscopy can see:

10micrometers-10nm (10^-5→10^—8m)

atomic force microscopy can see:

1micrometer→1nm (10^-5→10^-9m)

x ray crystallography can see:

10nm-1nm (10^-8→10^-9m)

brewers yeast (fungus)

Saccharomyces cerivisiae

resolution

ability to tell if 2 points are seperate

light microscopy

resolves images according to absorption of light

electron microscopy

uses beams of electrons to resolves small details

atomic force microscopy

uses intermolecular forces to see 3D cell

x ray crystallography

interference of x rays entering the molecule

bright field microscopy

object is dark against light passage

differential stain

stains one type of cell but not another

resolution

ability to tell if 2 points are seperate

light microscopy

resolves images according to absorption of light

electron microscopy

uses beams of electrons to resolves small details

atomic force microscopy

uses intermolecular forces to see 3D cell

x ray crystallography

interference of x rays entering the molecule

endospore staining

produced in some bacterial cells, protect against conditions, resistant to gram staining, appear green inside the cell

dark field microscopy

visualized as white against dark background, live, unstained samples

phase contrast microscopy

shows contrast between cells and background, showing organelles, live cells and their organelles

fluorescence microscopy

specimen absorbs light, emits lower energy light, shows parts of the cell

autofluorescence

some cell components naturally fluoresce under certain light

fluorophores

fluorescent compounds (FM4-64) or proteins (GFP, YFP, CFP) that fluoresce

immunofluorescence

identify disease causing microbes by observing whether antibodies bind to them

scanning electron microscope

beams of electrons, detects reflected electrons, shows 3D

transmission electron microscope

electrons transmitted to show an image, 2D

prokaryotes

small, no membrane bound organelles, 1-2 circular chromosomes

eukaryotes

large, membrane bound organelles, linear DNA with histones

prokaryotic subcellular structure

outer membrane, peptidoglycan, inner membrane, ribosome, nucleoid

fibriae

same as pillis

gonorrhea

Neusseria gonnhoeae

stalks

secrete adhesion factors to holdfast bacteria to environment

plasmids

found in some cells, small, circular, double stranded DNA, extrachomosomal, replicate independently of genome, codes not needed for everyday survival

transmission electron microscope

electrons transmitted to show an image, 2D

eukaryotes

large, membrane bound organelles, linear DNA with histones

prokaryotic subcellular structure

outer membrane, peptidoglycan, inner membrane, ribosome, nucleoid

fibriae

same as pillis

transformation

DNA from environment

transduction

DNA transferred via phages

conjugation

bacteria directly transfer DNA to the other via sex pili

amphipathic

polar/hydrophillic head, nonpolar/hydrophobic tail create phospholipid bilayer

phospholipid fatty acid chains

saturated: more rigidity

unsaturated: less rigidity

sterols

reinforcing agents, such as cholesterol (eukayotes) or hopanoids/hopanes (bacteria) to control membrane structure

fibriae

same as pillis

gonorrhea

Neusseria gonnhoeae

vertical gene transfer

parent to offspring, sexual or asexual reproduction; binary fission

plasmids

found in some cells, small, circular, double stranded DNA, extrachomosomal, replicate independently of genome, codes not needed for everyday survival

active transport

requires energy and transporter proteins, goes against a concentration gradient

mechanisms of horizontal gene tranfer

transformation, tranduction, conjugation

membrane spanning protein channels

substrate specific, require integral membrane proteins. from high concentration to low

symporters

active transport move 2 molecules in the same direction

plasmids

found in some cells, small, circular, double stranded DNA, extrachomosomal, replicate independently of genome, codes not needed for everyday survival

transmission electron microscope

electrons transmitted to show an image, 2D

cell envelope

protective layer for most species, cell wall plus any other associated layers

sterols

reinforcing agents, such as cholesterol (eukayotes) or hopanoids/hopanes (bacteria) to control membrane structure

archaeal membranes

isoprene fatty acid chains with methyl side chains every 4 carbons. fatty acid joined to glycerol by ethers. some have a monolayer, the fatty acids of the bilayer fuse, more resistant to harsh environments. no peptidoglycan; most contain proteineous S- layer

few species contain pseudomurein (pseudo peptidoglycan with N-acetylalosaminuronic acid (NAT) instead of NAM, stronger peptide bridges

methanochondrkitin is cell wall polymers in some archaea

integral membrane proteins

membrane spanning proteins

purpose of membrane proteins

support, environmental signals, communication, ion transport, energy generation, electron transport

stalks

secrete adhesion factors to holdfast bacteria to environment

aquaporins

facilitate osmosis, low concentration to high concentration

membrane spanning protein channels

substrate specific, require integral membrane proteins. from high concentration to low

symporters

active transport move 2 molecules in the same direction

bacterial cell wall compostition

requires energy and transporter proteins, goes against a concentration gradient

peptidoglycan consists:

N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)

what does penicillin target

transpeptidase: cross links peptides in the peptidoglycan

what does vancomycin target?

prevents cross bridge formation by binding to D alanine

S-Layer

surface layer on some prokaryotes, fit together like tiles, protective layer

lipopolysaccharide (endotoxin)

coat of polysaccharides, external to S-layer, protection, prevent phagocytosis,