History of Microbiology
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History of Microbiology
Final Exam Review
is the Golden Age of Microbiology?
A lot of discoveries where made during this time period.
Antonie Van Leeuwenhoek
Invented the first microscope(
simple microscope=1 lens
) called the things he saw
Used a compound microscope to discover that organisms were made of cells.
Started the first nursing program/helped care for soldiers
Invented the first vaccine against small pox
was the first surgeon to use aseptic technique.
First to use hand washing techniques/ greatly reduced puerperal fever.
Proved that bacteria caused disease.
invented vaccine against rabies/ also invented pasteurization
What is an Organic Molecule
A molecule that contains carbon and oxygen.
What is the function of a protein?
transport substances, allow for movement, catalyzing reactions and provide structure
disrups function and structure of protein
: phospholipids, fats,waxes, and steroids.
They are hydrophobic.
made from dehydration synthesis reactions
: double bonds
Esters of alcohol(contain alcohol in them) and fatty acids
difficult to breakdown
used for energy storage
4 rings ( contain 5 to 6 carbon atoms) that are fused to one another and also have various side chains.
Some act as hormones and maintain the structural integrity of membranes. as temp fluctuates.
made from carbon, hydrogen and oxygen
most contain and equal number of oxygen and carbon and twice the number of hydrogen
: amino acid sequence
: a-helix and B-pleated sheet
If solution leaves (
) then it is a base
If solution leaves (
) then it is an acid
is 8-14 on the scale
is 1-6 on the scale
(goes up by ten so 6 is 10x more acidic than 7
found in nucleus.
contain genetic material of the cell.
store and transmit info.
Made up of a phosphate group, a sugar and a nitrogenous base(carbon,hydrogen, oxygen and nitrogen).
acts like an enzyme and binds amino acids together to form polypeptides
made from three phosphate groups and adenine group.
: adenine and guinine
They are single ringed
: thymine, cytosine, uracil
3'' and 5''
DNA is structured this way. Said to be
called 3 prime and 5 prime because the end is located in carbon 3
DNA said to be semi conservative because each new DNA is made from an old parent strand and a new daughter strand.
is DNA synthesized continously
synthesized in short segments.
separates the DNA strands by breaking the H bond between nucleotides
replicates DNA by adding nucleotides to a hydroxyl group.
Start codon is
End Codons are:
Where: Occurs in nucleus, mitochondria. Plant cells have it in the chloroplast. Prokaryotes have it in the cytoplasm.
Process: RNA Polymerase reads gene and make a copy of DNA strand.
are non coding regions that must be removed my MRNA( only in eukaryotes)
regions that encode proteins.
4 Types of RNA
: molecules for DNA polymerase to use during DNA replication
: molecules which cary out info from chromosomes to ribosomes
: deliver amino acids to the ribosomes
: combine with ribosomal polypeptides to form ribosomes
3 types of RNA polymerase ( functions)
1. one for transcribing MRNA
2. one for transcribing the major RNA gene
3. one for transcribing TRNA and small RNA molecules
Storage (multiple substances)
magnetosome( navigation along magnetic fields)
The net movement of net particles from an area of high concentration to an area of low concentration( happens spontaneously)
The net movement of water from an area of low concentration to an area of high concentration,
across a selective permeable membran
: solute concentration same in and outside of cell
: high concentration of solute and high concentration of H2O
hypotonic:solution has fewer solutes and cytoplasm has more solutes
No energy required.
naming of organisms
invented by Carolus Linnaeus invented binomial nomen.
bacterial cell shapes
-circlular "ball" shape
- oval shape "pill" like
- spiral like shape
- cork like
- curved rod shape
- spherical and grow in pairs
- long thin "filaments"
obligate intracellular parasites.
have either DNA or RNA genome but never both( until 2010)
- nucleic acid genome, and a capsid
some have VIRAL ENVELOPES they get envelopes from the host cells they infect.
viruses without envelopes
icosahedron- 20 sided polyhedron
helical:spiral just RNA strand coated with proteins
bacteriophage- have both
determine host specificity.
bacterial chromosome degraded
synthesis-alot of viral replication
genome is injected inside, while capsid stays outside
only envelope viruses do this
glycoproteins remain in the host membrane while the virus merges with the host.
glycoprotein in viral membrane binds with membrane protein in host
cytoplasmic membran engulfs virus
host cell membrane wraps around viral membrane
viral genome bust out onto host cell
What determines HIV's host range?
how does HIV infect a host cell?
GP 120 binds to the CD4 receptor of a host cell
when this happens CXCR4 arrives and binds
when this happens the head(GP120) falls off which exposes GP41
that causes the viral envelope to fuse with the host cell
causing the release of the viral capsid which contains genome and proteins
causes the above the waist lesions
causes the genital lesions
region of skin enervated by skin
less serious as a child
could come back as shingles "herpes zoster"
caused by burkitts lymphoma and infections mononucleosis
you get it as a young child
first virus that showed it could cause cancer!
Bacteria divide by
growth in prokaryotes occurs in terms of
population not size
eukaryotes grow in terms of
prokaryotes reproduces to
an identical clone of the parent cell and acts the same
eukaryotes reproduce to
stem cells- could turn into different cells
1. cell elongates and DNA is replicated
2. Cell wall and plasma membrane begin to grow inward
3. cross-wall forms completely around DNA
4. cells seperate
phases of bacteria in a closed system
lag phase- detecting environment
log phase- their growing
stationary phase- growth levels off
logarithmic decline phase- population overal are dying.
additive vs. exponential
additive- cells divide by 1
exponential- cells double(more numbers)
bacteria has___________ when in a certain temperature.
Blood agar is...
a complex differential medium
alpha hemolysis- partial destruction
beta hemolysis- complete destruction
gamma hemolysis- no destruction
is both differential and selective
kills gram positive bacteria
differential for lactose fermentation
bacteria that moves is called____
controlling microbial growth
has to do with food and public health
on non living objects or surfaces
on living tissue clean of bacteria
the killing of all microorganisms
high temp. high pressure
hot air oven, incineration
tyndallization control endospores
boiling and reboiling- kills spores you reboil because spores could regerminate
pasteurization-rapid heating before boiling point
chemical methods of control
irradiation- uv radiation
soaps and detergents-removal surfactant activity
gas- kills microorganism used on antiques
antibiotics- used to remediate living organism
antiseptics and disinfectants- chemicals used on surfaces
Antibiotics three types
antibiotics are any chemical that kills any organism
1. salverson- 1st gen. toxic to host cells
2. sulfa dogs- 2nd gen. metabolic reaction/ allergic reactions
3. natural products- 3rd gen. penicillin
add a phosphate group
any enzyme that phosphorylates something
4 major resistance mechanisms
1.chemically modify antibiotic compound
2. mutate target structure
3.MDR efflux pump( protein pumps out drug)
4 reduce permeability ( block uptake)
3 mechanism for controlling bacterial growth
bacteriostatic- stop bacteria from dividing stop population from growing
bacteriolyctic- physically destroys bacteria
bacteriocidal- example raid
triggered by nutrients deprivation
cell dies but spore doesn't
germination happens when there is nutrients.
monotrichous- have only one flagella
iophotricous- have many flagella that originate from one side
amphitricous- have flagella on both sides
peritricous- have flagella on all sides
movement towards an attraction or away from repellant
really hard to make
guanine analog- could be used instead of guanine
blocks nucleotide polymerization
Enzyme is ....
an organic catalyst
something that speeds up a reaction/ makes it likely to happen
is a vitamin
an enzyme with both a cofactor and a coenzyme
if other parts are present than there are other parts
sum of all reaction in a cell
a build up of small molecules into larger molecules
was the first person to show that microorganisms cause disease
4 conditions( koch postulates)
1. suspected germ present in all cases of disease
2. germ must be isolated and grown in pure culture
3. isolated must cause disease when injected in normal healthy host
4. the same germ that was injected must again be isolated
5 stages of disease
incubation period- no signs or symptoms
prodromal period- vague general symptoms
illness- most severe signs or symptoms
decline- declining signs and symptoms
convalescence- no signs or symptoms
signs vs symptoms
signs- things detected by other people
symptoms- things only detected by you
engulfment and destruction of a foreign body
1 pseudopod moves outward to engulf the microbe
2 once inside they are carried in phagosomes
3 lysosomes dump their contents by fusing to phagosomes
4 killing by enzymes and chemicals
5 elimination by exocytosis
virulence vs. virulence factors
- ability to cause disease
- some component or product that allows microbe to cause disease
bacteria secrete toxin outside host cell
kills host cells
dead gram neg. bacteria release endotoxin( lipid A)
enzyme destroys hyalyronic acid- which helps cells stick together
when this process happens the cells lose the acid and do not stick allowing bacteria to enter
destroys collagen which makes tissue elastible
causes blood clots which allow bacteria to be hidden
extracellular matrix of polysaccharides secreted by bacteria only on surfaces
mechanism by which bacteria detect population numbers
2 organism live together in close association
containing no foreign or non self organisms
microorganisms that live together with eukaryotes
both bacteria and host benefit
1 benefits and the other doesn't and neither is harmed
one benefits the other is harmed
Ang 4 functions
kills bacteria in gut
and is angiogenic formation of blood vessels
first line of defense
blocks 99.9 of bacteria
second line of defense
response of vascular tissue to harmful stimuli, such as pathogens or damage cells
something that can stimulate and immune response
blood travels in _____
lymph travels in______
structures that serve as the structures that serve as the sites of cell to cell communication
bind to antigens
foreign molecule that causes immune response
CD4 binds to
CD8 binds to
type of B cell make antibodies
type of B cell
provide immunological memory
pathogen is killed but retains normal shape
pathogen is alive but it is crippled so that it can no longer cause disease
a surface protein form the pathogen is used
third line of defense is
bacteria that lack a particular nutrient or the ability to synthesize that nutrient
used to identify mutants
small circular, extrachromosomal DNA molecule
origin of replication
determines high or low copy
happens by crossing over of DNA strands
horizontal gene transfer
horizontal because it happens in the same generation
marriage between two bacteria
multiple genes under one control
3 parts of operon and function
promoter- nucleotide sequence that enables a gene to be transfered
operator- a segment of DNA that a repressor binds to
structural gene- regulated by operon
regulatory gene- regulate operons
inducible operon( normally off but could be turned on)
genes in lac operon responsible for the breakdown of lactose
lactose is inducer
human made strand
may be unicellular or multicellular some of them could switch between both