Microbiology Exam 2

Ivan IV

The first Czar of Russia

-started out leading an enlightened reign with progressive changes in Russia

-Due to paranoia caused by syphilis, he causes mass murder and torture

• gets nickname “the terrible” due to this

plague of Athens

430 BC = war of Sparta vs. Athens

-Athenians crowd into dense urban environment (no sanitation)

-plague wipes out between 1/3 to 2/3 of population

Thucydides

wrote about the plague of Athens and was the first one to notice that only the survivors were able to help the infected

scarlet fever

streptococcus pyogenes

the best guess for the cause of the Plague of Athens

malaria

one of the causes for the fall of the Roman Empire

-this disease establishes itself, becomes widespread, consistent loss of life

-leads to a decrease in agricultural output

roman climate optimum

Another reason for the fall of the Roman Empire

-the climate of the Roman Empire changed and then the movement of people west and east made the existing changes even worse

Plague of Justinian

540 AD = Due to the BUBONIC PLAGUE, this plague caused up to 5000 deaths per day.

-due to the mass deaths, the grave diggers cannot keep up and lead to mass graves and hasty disposal.

-Empire begins to destabilize and loses the most territorial gains

bubonic plague

Bacteria : Yersinia pestis

-Vector = fleas

-causes high fever, swollen glands (buboes) in armpits and groin

-buboes rupture = gangrenous lesions

-can be spread via respiratory droplets

-still around in N. America and can be treated with an antibiotic

Black Death

this leads to the loss of 24 million people

-destabilizes countries and empires

-stops Viking expansion into North America

-Ends serfdom and the role of peasant wages due to everyone dying and peasants getting more say in what happens with their land

smallpox

The Spanish invasion of the Aztec Empire brought what disease?

-before disease = 15/30 million people

-after disease = 2/3 million people

-HAS SINCE BEEN ERADICATED

monocultures

no variation in population, disease will spread very easily

-this is what caused the Irish Potato Famine

• wiped out potato crop in Ireland

French Panama Canal

malaria and yellow fever lead to the collapse of this

The Americans are able to take over this idea and create their own Canal after they connected the dots to the disease being spread by mosquitos

Robert Hooke

The first person to publish a description of cells (1600s)

-DEVELOPED RUDIMENTARY MICROSCOPE

Antonie van Leeuwenhoek

The first person to describe bacteria (1674)

-Created better magnification on microscopes and actually visualizes bacteria

spontaneous generation

the belief that life can arise from nothing/nonliving items

Francesco Redi

(1600s) Person who first tested theory of spontaneous generation

-believed that maggots arise from nothing

-had an open jar of meat, a gauze covered jar and a sealed jar.

-only the open jar developed maggots

-DETERMINED THAT YOU NEED LIFE TO GENERATE LIFE

Louis Pasteur

person who definitively put the idea of spontaneous generation to death (used straight neck

-also created pasteurization and vaccination of anthrax and rabies

-contributed to the Germ Theory of Disease

biogenesis

idea that life arises from existing life

pasteurization

characterized fermentation

-Pasteur realized that heating wine prevented stored wine from turning bitter (bacteria making acetic acid)

-carried over into milk, juice and wine

fermentation

yeast cells release alcohol as metabolic waste in the absence of oxygen

attenuation

systematically weakening a pathogen

-Pasteur realized that with a weakened virus, the disease won’t kill you, and the body will still recognize the pathogen in the future

germ theory of disease

the idea that microbes cause disease/infections

-previously thought to be caused by an imbalance of bodily fluids (humans), foul air (miasma), evil spirits, or divine judgement

etiological agent

a causative organism

-ongoing process (we can culture ~2% of bacteria)

Robert Koch

(late 1800s)

-developed staining techniques

-created media for isolation and cultivation of organisms

-pure culture developed

-groundbreaking work with anthrax

Koch’s Postulate #1

The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms.

Koch’s Postulates #2

The microorganism must be isolated from a diseased organism and grown in pure culture.

Koch’s Postulates #3

The cultured microorganism should cause disease when introduced into a healthy organism.

Koch’s Postulates #4

The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

Koch’s Postulates

developed by Robert Koch to help determine the causative agent of disease

Ignaz Semmelweis

Hungarian physician in mid 1800s

-Childbed fever = puerperal sepsis

-connected dots between med students working on cadavers and then helping deliver babies

-recommended hand washing

-nobody believed him, driven away

Joseph Lister

-inspired by Semmelweis and Pasteur

-Aseptic surgery

-Suggested washing instruments with carbolic acid

-encouraged healing, prevented pus formation

Florence Nightingale

-pushed for aseptic techniques in nursing practices

-founder of modern nursing

Semmelweis, Lister, Nightingale

who were the three people that made advances in general sanitation?

Paul Ehrlich

1906

-working with stains for cells, tries to develop “magic bullet” against bacterial cells

-Salvarsan = compound to fight syphilis

-developed Sulfa drugs (entirely synthetic with same effect as antibiotic)

Alexander Fleming

1929

-Created Penicillin (antibiotic)

antibiotic

anti-bacterial compounds produced by other microorganisms

Watson and Crick

who were the two people that determined the structure of DNA and that it is a double helix?

genome

the entire collection of genetic material in a cell or virus

gene

the heritable units of genetic material that define a particular trait (located within genome)

-more complex the organism is, the more genes it will have

genotype

genetic makeup (the recipe to build a phenotype)

phenotype

the physiological or physical traits

Deoxyribonucleic acid

long name for DNA

ribonucleic acid

long name for RNA

chromosomes

genome is organized into packaged strands of DNA called these

-number does not influence organism completely

histones

specialized proteins (spools) that wind and tighten DNA to condense it to fit into chromatin

-play role in how we read DNA

prokaryotes

1-3 chromosomes

-typically circular

• with scaffolding proteins

eukaryotes

contain numerous linear chromosomes

-uses histones

-contain mitochondria and chloroplasts

plasmids

resemble prokaryotes

-circular and extrachromosomal

nucleic acids

built from nucleotides

nucleotides

made with a phosphate, sugar (deoxyribose or ribose) and a nitrogen base (pyrimidine or purine)

ribonucleotides

RNA’s name for nucleotides

complementary

DNA is a double helix with _________ strands

-if you know the one strand sequence, you can determine the other

single

RNA is often ____ stranded

antiparallel

DNA strands are _____

-DNA is built from 5’ to 3’ and to add nucleotides, you need a free 3’ carbon attached to a base/phosphate

5, 3

DNA is built from ___’ to ____’

central dogma

the idea that DNA directs the production of RNA and RNA directs the assembly of proteins

-the flow of information in one direction

-living organisms all go from DNA to RNA

DNA replication

the process by which a cell copies its genome before division

-typically very fast and accurate

mutations

technical term for an error in DNA replication

-1 of these per 10-100 billion base pairs

origin of replication

-1 in prokaryotes

-multiple in eukaryotes

-where the DNA strand starts out being read/copied

leading strand

the strand that has continuous replication by DNA Polymerase III (5’ to 3’)

DNA polymerase II

an enzyme involved in DNA replication in prokaryotes. It is responsible for synthesizing the new DNA strand by adding nucleotides in a 5' to 3' direction

DNA polymerase I

an enzyme involved in DNA replication that replaces the RNA primer with DNA

Ligase

an enzyme that catalyzes the joining of DNA fragments by forming phosphodiester bonds between adjacent nucleotides

Lagging strand

the strand that has discontinuous replication by DNA Polymerase III

-Okazaki fragments

-DNA polymerase I and Ligase remove and replace primers

okazaki fragments

short, newly synthesized DNA fragments that are formed on the lagging strand during DNA replication

semiconservative

DNA replication is ____ because there is 1 parent strand and 1 new strand

gene expression

makes proteins

-synthesizes these proteins through transcription then translation

nucleus

where does transcription occur in eukaryotes?

cytoplasm

where does transcription occur in prokaryotes?

RNA polymerase

binds to promoter

-pairs complimentary ribonucleotides (U pairs with A)

-continues until it hits the termination sequence

transcription

the process that turns DNA into RNA

exons

these are glued together after the removal of introns in mRNA in eukaryotes

introns

all of these are removed in eukaryotic cells following mRNA splicing

spliceosomes

this is what removed introns

alternative splicing

results in a different protein

-can build different smaller pieces from one large stretch of RNA

-one gene might give three proteins

mRNA

carries a genetic message in a triplet code (codon) and is then translated to build a protein

-whatever we just built using DNA as a template

tRNA

cloverleaf shaped molecule that serves as an adapter molecule to usher amino acids into the ribosome during translation

-folds in on itself, nucleotides interact with each other

rRNA

takes on complex stem and loop structures and combines with proteins to build ribosomes

-whatever RAN is needed to create a ribosome

codon

this codes for 1 amino acid

-set of three nucleotides

Translation

protein synthesis from mRNA template

cytoplasm

where does translation occur in prokaryotes?

cytoplasm (rough ER)

where does translation occur in eukaryotes?

EPA

the binding sites for tRNA on ribosomes (from left to right)

anticodon

a sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.

polycistronic

mRNA is commonly this

-one big stretch of mRNA might have several genes on it

-because transcription and translation occur in the same location, you can make multiple proteins off the same mRNA

post translational modification

-making some changes after translation

-regulates how often mRNA is made into proteins

-addition of organic and/or inorganic factors

-trimming of amino acid sequence

-often required for proper protein function

20

approximately ___ % of a cell’s genes are expressed at any given time

constitutive genes

housekeeping genes in regulating protein synthesis

facultative genes

regulated genes that are either turned on or off

operons

collection of genes controlled by shared regulatory elements

-promoter, genes, repressor, operator

inducible operon

operon that is OFF by default

repressible operon

operon that is ON by default

off

lactose operon

-E. coli

-Glucose

-no lactose

IS SYSTEM ON OR OFF

On

lactose operon

-E. coli

-no glucose

-lactose

IS SYSTEM ON OR OFF

on

arginine operon

-E. coli

-arginine low

IS SYSTEM ON OR OFF

off

arginine operon

-E. coli

-arginine high

IS SYSTEM ON OR OFF

substitution

mutation where an incorrect nucleotide is added (typo)

insertion

mutation where there is an addition of one or more nucleotides (shifts sequence)

deletion

mutation where there is a removal of one or more nucleotides (shifts sequence)

silent mutation

changes a base, but still codes for the same amino acid (mutation that didnt matter/cells dont notice)