MICRO EXAM 1

microbes classified by comparing microbial genomes

viral genomes can be RNA or DNA

prokaryotic cells

• no true nucleus or nuclear membrane

• includes bacteria

Eukaryotic cells

• have true nucleus

• funngi, protozoa (single-celled), helminths

viruses

• non-cellular, non-metabolic

• unable to produce independently (has to invade other cells)

• genes aren’t always made of DNA

robert hooke

first to use the term “cell”

anton van leeuwenhoek

• first to observe bacteria and protozoa with a single lens microscope

• father of microbiology

louis pasteur

• developed pasteurization technique

• his work led to prove the germ theory of disease

florence nightingale

demonstrated the statistical signifigance of martality due to infectious disease

ignaz semmelweis

promoted hand washing by medical professionals

joseph lister

began use of chemical disinfectants during surgery

John snow

discovered cholera was spread via water

robert koch

isolation of pure cultures on agarhai

chain of infection

diagnosis requires direct evidence that a given microbe caused the disease (robert koch)

koch’s postulates

links pathogen with a disease

• cant always be applied

edward jenner

father of immunology

alexander fleming

mass production of penicillan gave birth to pharmaceutical industry

ivanovsky and beijerinck

first to use term virus

polymerase chain reaction

makes many copies of a specific DNA sequence from a small sample

• kary mullis

• detecti9on and identification of microorganisms

pathogen

any bacterium, virus, fungus, protozoan or helminth that causes disease in humans

more pathogenic

more deadly

colonization of microbes

• microbiota or flora - collection of all microbes (abundant in intestines and mouth)

  • not present in CNS, cardiovascular system, lungs

infection

pathogen or parasite begins to grow on host

• usually asymptomatic

  • acute infection - common cold

  • chronic infection - tuberculosis, HIV

Primary pathogens

cause disease after infection in a healthy host

• influenza

opportnistic pathogens

immunocompromised

• pseudomonas (CF), pneumocystitis

latent infection

pathogen lives lifelong in host

• herpes, HPV, HIV, EBV, CMV

virulence

level of harm/ danger caused by pathogen following infection

• factors: toxins (botox), enzymes, adhesions, anti-phagocytic capsule

sequelae

disease resolves, consequences develop weeks to months later

• immune response to strep throat causing heart damage weeks later

prodromal

showing initial symptoms of acute infectious disease (fatigue/malaise)

fomites

inanimate objects that transmit diseases (door handles)

endemic

always prsent in one community at a low rate

epidemic

number of cases in a community increase in a short amount of time (escapes reg endemic community)

contracting infectius disease factors:

#1 hygiene and behavior

• genetic make up (genetic predisposition)

micrometer range

10-6

• protozoa and bacteria

• light microscope/stained samples

nanometer range

10-9

• viruses

• electron microscopy

differential stain (gram stain) order:

1. purp

2. iodine

3. alc

4. pink - safronin

• thick - gram pos (purp)

• then gram neg (pink)

acid - fast stain

blue with drak purple lines

flagella stain

pink with squiggles coming off of them

endospore stain

glass looking, blue spots on it

CHONPS

98% of the mass of living organisms is made up of carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur

macromolecules

carbs, lipids, proteins, nucliec acids

carbs

monosaccharide - glucose

disaccharide - lactose

polysaccharide - ceelulose, chitin

primary structure

linear sequence of amino acids

secondary structure

aplha helix

beta-pleated sheet

tertiary structure

unique three-dimensional shape

guaternary structure

some protiens

functional complexes formed with other proteins

DNA double helix

sugar - phosphate backbones

genetic code for protein synthesis

RNA forms

• mRNA - single stranded, contains codons (U instead of T)

• tRNA - carries amino acids to mRNA, contans anti - codons

• rRNA - ribosome

• influenza/ HIV have genomes made of RNA (HIV = retrovirus)

prokaryotic cells

• no true nucleus (no nucleur membranea)

• do not contain membrane bound organelles

• bacteria + archaea

Eukaryotic cells

• NOT VIRUSES

• nucleus and other organelles

• animals, plants, fungi, protozoa, helminths

Bacterial cell structure

• cell wall, plasma membrane, dna in cytoplasm, ribosomes present

• external appendages (flagella - movement, cilia - movement, pilus - horizontal gene transfer)

bacterial cell envelope

plasma membrane

• can also have a cell wall located outside of cell membrane (peptidegycan)

• gram- negative- additional membrane outside cell wall (outer membrane)

gram positive cell wall

• thick cell wall, multiple layers of peptidoglycan

• bacillus and clostridia/ staphylococcus and streptococcus

gram negative cell well

• thin cell wall, single layer of peptidoglycan, enclosed by additional outer membrane

• escherichia coli, pseudomonas aeuginosa

lipopolysaccharide (LPS)

• large sugar/lipid molecule extending from outer membrane

• lipid portion acts as endotoxin in lysed cells, so antibiotics can kill cells but also can cause endotoxic shock in patients

mycobacterial envelope

• complex cell wall with mycolic acid

• resistant to staining

• mycobacterium tuberculosis

bacterial nucleotide

not true nucleus ( not bound)

• extra DNA called plasmid in some bacteria (conveys virulence factors and antibiotic resistance)

bacterial ribosomes

• structurally different but similar to eukaryotes

• important in slective toxicity (targets things in bacteria we don’t have - like the structurally different ribosomes)

eukaryotic cell

• plasma membrane

• nucleus w DNA

• endoplasmic reticulum

• ribosomes

• golgi apparatus

• mitochondria

• lysosome

• peroxisome

• centrioles

transcription

DNA to mRNA in nucleus

translation

• ribosomes

• codons (3 letter) code for amino acids

• codon of mRNA matches w anti-codon of tRNA (a-u/c-g)

• tRNAs bring amino acids which eventually form protiens