VB Notes
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Viruses are like hijackers who invade and take up all of their stuff and reproduce to eventually kill
obligate intercellular parasites
must get into a host cell
Viruses can infect all cells
virsues
all have one core of nucleic acid
dna or rna; single or double stranded
capsid
coat and protects the dna and rna
always made of proteins
isosahedral - 20 sides
helical - rod shaped
some have
envelope
kind of like a membrane
enzymes
usually needed for viral replication of transcription of genes
virirod heads
naked rna, no caspid that affects most plants
viral infection - stages
adsorbption
vrius attaches or interacts with the host membrane
viral proteins that bind to host cell receptors
viruses must have the rind binding proteins to match with cell receptors
which is why viruses usually only target certain cells
penetration
take in the virus in a vesicle
called recepetor mediated endocytosis
uncoating
synthesis
syntehsis of viral components such as caspid proteins, viral enzymes, envelope proteins, and nucleic acid
assembly
assemble diffferent virus components to produce an intact virus that can infect another host cell
release
eneveloped virus
spike proteins on the membrane are on it as they release
non-enveleoped (naked) burst and release all the naked viruses
lytic and lysogenic cycles
lytic cycle - think active, infect others
host cell = host cell death
virus detects lysozyme cell, break it open host cell and viruses are release, virus kills the host cell called lytic viruses and are virulent in that thye kill their host
start making more
lysogenic cycle - think lets chill, dormant, latent till the conditions get better
restriction enzyme and enter the latent stage (dormant)
host cell is not killed
enters the genome called prophage
temperate phage - can undergo a lytic cycle again
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reproductive strageties of virus
three main types
dna viruses
examples
herpes
chicken pox
cold sores
hepatitis
smallpox
papillooma
hpv
rna viruses
acts as an mRNA for immediate translation
as a template to produce more rna genome
if virus enters and made of rna, then immediately that rna can be translated and take the host ribosomes and tralsate it into proteins
protease early gene thats transcribes and translated for snipping
viruses must carry the code (the enzyme) to make more rna with rna
examples
polio
rabies
influenza
rhinovirus
retro viruses
is rna a virus but called retor because it holds reverse transcrpase in caspid
take a strand of rna, a complemetnary strand of dna, and could make the dna double stranded and make proteins, and then also take the end and put it into the host genome
you could be infected of hiv, and be dormant in your dna for years and decades without you knowing it
integrase
hiv is enveloped with host cell membrane
HIV
gp120 spike proteins of hiv
viral orgin
reverse transcriptase very poor proof reading abilty
rate o fmutation in the virus is high
and immuse system has hard time recognizing secondary infections because virus is different
spike proteins are translated into the rer
diseases associated with hiv
people started typing of either rare infections/diseases or very simple disease
kaposi sarcoma skin cancer
pneumocytisis carinin - pnemonia caused by fungus
no true cure for hiv because it is always constantly mutating
general treatement
vaccines
memory cells so that if your body gets exposed to it, your body can recognize that infection
If you get the flu vaccine, you can still get it
mrna vaccines
you can optomize mrna when youre ribosomes
antiobitics
interfereon
viruses can cause cancer
if it can incoprorate dna into the genome, then that could disrupt genes, and if those genes happend to be very important thnen and stop doing its job divide divide divide causing cancer
orgin of viruses
fragment of cellular genomes
pieces of genomes of cells and worked with, got special packing, with caspid,
infectious agents
viroids
naked pieces of rna that acts like sirna (inteference rna) and shuts them down
Bacteria
2/2/26
general classification
prokaryyotes into 2 domaains
domain bacteria
includes most prokaryotes it includes most organisms know as bacteria
doman archaea
methagnogens
halophiles
thermophiles
taq polymerase - form thermas aquatics bacteria
can withstand the hot temperatures
comparison of three domains of life
absent doesn’t mean that theres no cell its just that its not made of pepttoglycand (what plants need to make cells)
so bacteria do have cell walls just not make of peptoglygang
bacteria do not have histones, but archcea and eukarya do
bacterial cell structure
flagella
for motility
whip liek tails, can have one or more
pilli
extensions from the cell that aid to host
capsule
sticky film outside of cell wall
can make bacteria pahtoygenci and evaded by white blood cells
made of lippopolysaccharide
found in gram negative bacteria
cell wall
gram positive bacteria
less pathogenic
gram negative bactera more pathogenic
after full gram staining process
layer that is stained, when washed is purple, layer that is immune
know why gram + thick cell wall, will stain and stay purple’ gram negative thin cell wall, will iniitally be purple then be pink
gram negatives tend to be more pathogenic
three ways cells echange dna
conjugation
hfr high refrequence recombination
has the plasmid but the real trait to incorpate the dna then into the pillis
f+ or fhr called “male bacteria” because they can form the male pillis
transduction
transformation
transposons
jumping genes
present in bacteria
bacterial metabolism
bacteria very diverse
all have different metabolic strategies
oblige aerobe: can’t survive without O2
obligate anaerobe: poisoned in the presence of o2
faculative anaerobe: anaerobic or aerobic on different conditions
important functions of bacteria
decompoers break down organic matter
photosytensis
cynobacteria absorb light energy and fix organic compounds
symbiotic bacteria
mutltulism
host and symbiont benefit
commensalism
symbiot benefits host doesn’t gain or lose anything
parasitism
Symbiont benefits at expense of host
bacteria and disease
pathogenic bacteria
release toxins, destroy hot tissue
discovered antioboitcs
penicillin discovred by alexander felmming that stops infection
Endospores** (one question on test)
Some bacteria that produce this
when enviornment is not optimal, bacteria form a spore (vault) around its dna to protect it
And when the enviornment gets better, it can then start growing again
putting bacteria to work for us
recombinant dna techniques
production of antiobiotics
prepartion of food - fermentation - cheese, vinegar, yogurt
breakdwon of waste in sewage treatment plants
IMMUNTE SYSTEM
antigens
any substance that can produce an immune response
virus, bacteria, fungus, protosen, pollen
protein or polsaccharide
Epitopes
spots that can be regonized and bound to your immune cells
antibody (ab)
y shaped protein created by your immune system
cellular components of immune system
stem cells in bone morrow give rise to all blood cells
stem cells in bone marrow - white blood cells
erthrocytes (rbcs)
leukoyotes (wbcs)
non lymphocytes
basophils
eosinophils
neutrophils
macrophages
dendritics cells
lymphocytes
t cells
t helper cells
cytotoxic t cells
suppressor t cells
b cells
plasma cells
thromobocytes
platelets
big picture: immune response
1st line of defense
innate barriers - physical
built in genetically - chemical
2nd line of defense
innate phagocytes
3rd line of defense
acquired
lymphatic system
immune cells love to hang around the lymphatic system in either —
thymus
bone marrow
lymph notes
spleen
tonsis, adenoids
all of these wait for bactera/infections to pass by and recognize the antiogen
b cells mature in bone marrow
t cell move to thymus and mature there
immune system chemicals
cytokines
hormone like molecules secreted from cells of the immune system
interferon - given off by viral infected cells
inflamatorry response
histamine
released from injured cells
acquired immunity
the immune response
humoral immunity
invovled the b cell response
cell mediated
cells are infected
mhc I and mhII moleucles
mhc stands for major histocompability comple
our cells have trophies
displays a piece of bacteria in the mhc like a roman empire would put their opponents on pikes their head like a trophy telling everyone else look for these pieces of bacteria
you do not have one mhc for each infective agent
each persons mhcs are unique to themselves
during transplant for tissue/organ etc, both people must have the same mhc’s or else it will reject the new part
part of the mhc involves the endomembrane system where the golgi and vesicle transport the “head on the pike” displaying the bacteria onto the mhc on the membrane
Clonal selection of B cell
antibody functions
do not need to know the 5 classes of antibodies
do need to know why antibodies are potent
neutralizing foreign substances
agglutinates cells
clump the bacterial cells together to prevent them from functioning
ehances phagocytosis
antibody structure
long designated by H for heavy
and short for light
4 different polypeptides, two light and two heavy
quatenary structure
c represent constant region that doesn’t change
antibody diveristy
v for varialbe - 30-40 different combining genes
with different joining regions
when b cells are diffrenetiaed and kinda growing up, some dna is cut out, and get rid of the rest
like dealing out a deck, dealing 5 cards then tossing the other
want unique antibody/receptor and keep the dna so if you want to clone that the dna you still have it again
clonal selection when one b cell has the right receptor can make identical
stem cells have all the dna but mature b/t cells (genes for making the receptors) have the dna needed
must do the recombining for light and heavy chains; and can make these for several different antibodies
types of immunity
active immunity
done and triggered by a vaccine (tricking your immune system so it has the same response)
passive immunity
fighting smth off without any memory cells
examples
give anti-serum to snake or spider bite, and no future protection
mom can pass antibodies to the baby through breast milk so that it can have a stronger immune system before it starts to develop their own
disorders of immune system
allergy
pollen, foods should not cause a reaction but its the immune systems reponse to it (itchy, swelling, redness)
2/11 additional immune notes
t helper has cd4 receptor mhc 2
cytotoxic cd8 receptor mhc 1
puncing membranes causing lysis - and be gobbled up by macrophages
interlookin are a type of is whats secreted from the macrophages and t cells
do not memorize the types on that additional informaiton page