Bio 1114 Exam 3

viruses

based on what we can see, not cellular, not living, considered non-cellular infectious, scientists disagree on where they belong, can infect anything

viral components

1. genetic core (RNA or DNA) 2. tough protein outer capsule/coat that coats genetic core

DNA viruses

pox viruses (smallpox, cowpox), herpesviruses (herpes, varicella), herpes and chicken pox, hepanaviruses (hepatitis B), liver disease

RNA viruses

togaviruses (rubella, German measles, chikungunya fever), filoviruses (ebola, marbug, hemorrhagic fevers) retroviruses (HIV, AIDS)

viral infection process

virus cannot replicate themselves so they must infect a living cell to reproduce, living cell is tricked to making more virus, infected cell does all the work and manufactures new viruses

copier analogy for viruses

original in top of copier, and then it makes multiple copies quickly

infection steps

viral attachment, viral penetration, DNA formation, viral DNA incorporation, component construction, assembly & release

viral attachment

virus physically attaches to host cell, specific receptor on host cell that virus attaches to, head/tail/fiber tail fits into receptors, DNA of virus can enter

HIV- viral attachment

spikes called GP 120 glyoprotein attach to CD4 receptors on certain white blood cells

warts effect

skin, wart virus fits in skin receptors

influenza effects

lungs, influenza virus fts in lung receptors

herpes or pox effects

nerve, this is why its permanent, makes copies, soma carries the virus and dendrites push

why is herpes permanent in humans

the virus invades the nerve cell body, once in nerve cells it is permanent, hidden from immune system

viral penetration

entire virus or just genetic material enters the host cell

HIV- viral penetration

RNA molecules enter

DNA formation

viral genetic material is converted into DNA

HIV- DNA formation

RNA molecules are converted to DNA (this is skipped in DNA viruses) reverse transcriptase convertsRNA to DNA quickly

viral DNA incorporation

viral DNA is incorporated into host cell DNA, splicing method, infection can be permanent after step as long as at least one infected cell remains alive

component construction

host cell makes all necessary parts to form new viruses

assembly and release

host cell assembles pieces into new viruses can potentially affect neighboring host cells or other host cells in new organisms

budding

release pathway, singular or few viruses released, drippy water faucet

lysis

large number of viruses releases, host cell usually bursts open and releases

HIV- assembly and release

budding or lysis route, depends on state of white blood host cell

west nile virus

enters but doesn’t go into nucleus, also affects nerve cell, typically birds→mosquitoes→rests in mosquito salivary gland, in horses 40% deadly, humans slightly deadly

influenza

pathogen, RNA virus, 3 types A, B, C, affects lung tissue, mostly affects the old or young

deaths from influenza per year

20,000 in US

natural reservoir

brings back to US each year

natural reservoir- for influenza

birds, inhalation avian flu cases, went directly from to bird to human, more common human to human, since lung proximity is an issue

influenza pandemic in 20th century

1918, 1957, 1968

1918 influenza pandemic

spanish flu, 50 million deaths, first case base in kansas

1957 influenza pandemic

asian flu, 1-4 million deaths

1968 influenza pandemic

hong kung flu, 1-4 milion deaths, dodge went to car show in 1919 got flu and died, woodrow wilson- walked in on in-flew-enza

MMWR

mobility mortality weekly report, US tracks weekly

antigenic drift

replicated cell cycle thru leaves with new small mutations, can result in different shape, slight drift

antigenic shift

multiple infection strains occurring at same time- influenza A, B, C, can create a new strain that have pieces of all strains

farmers should keep birds and swine separate to prevent

antigenic shift, swine can have both non-human and human form, can jumble together to make new strain

influenza virus shift

bird→swine→human

flu shots every year

antigens on virus change so antigenic shift due to mutation, new virus evolves, body does not recognize antigen means new infection, flu shots contain many antigen versions

soap

spheres of hydrogen, similar to phosolipid (hydrophobic non-polar end and hydrophillic polar end), soap can break apart viruses, prevents step one! (viral attachment)

commmon cold

200+ viruses, virus and nasal membrane, as you age you get less because of built immunity

myths

wet hair makes you sick. no because colder weather induces shivering and nasal membranes produces more mucus, but exposure to virus is what causes the cold

milk

study done that compares people producing mucus to those who drink milk

sneeze

particles travel 2-3 meters, reach 150 km/hr

prions

pathogenic protein that formed into different structure and cause other proteins to do same

john stanley griffith

proposed mechanisms that things that no genetic material are capable of reproducing

stanley b. prusiner

named prions, nobel prize, found protein can replicate without genetic material, proved john stanley griffith right

shape of protein

determines its function

prion protein misfolding

protein becomes disease-causing when it misfolds into an abnormal shape, this rogue form can convert normal proteins into the same misfolded shape, creating a chain reaction.

spongiform encephalopathies

cause nerve tissue to become spongy, prions puncture holes in the nervous system and causes the brain to become spongey, irreversible and permanent, loss of motor functions, can’t do any type of task, typically fatal

mad cow disease

cows-beef needs to be recalled because it has prions and is irreversible and it can cause the humans to get infected

scrapie in sheep

called this because it makes them very itchy, they will start ripping their skin off until they kill themselves, once one sheep in the herd has it they have to kill all of them

chronic wasting disease (deer/elk)

makes them feel so full that they can’t eat, they will starve themselves to death and they die. 100% deadly, don’t know if it can be transferred to humans, ohio as a state will test deer for free for hunters, spread by contaminated body fluids, consumption of infested items

normal disinfection methods do not work on prions

can kill at 160 degrees, temperature can make it safe for consumption, even if you cook it until ash and it will still have it (tested by stanley prusiner on mice)

prior to 1970

2 kingdoms- plantae and animalia

post 1970

5 kingdoms- monera, protista, plantae, fungi, animalia

now

3 domains- bacteria, archaea, eukarya

prokaryotes have existed

3.5 billion years, for ~1.5 billion they were only living organisms, most successful on plane, can live in any environment (aerobic, anaerobic, upper atmosphere, ocean depth, miles below earth, some bacteria can be benefical

prokaryotes

lack membrane bound organelles, asexual reproduction

number of bacteria in mouth

greater than the total number of people who have ever lived

bacteria and archaea

2/3 domains of living organisms, lack membrane bound organelles, have circulat DNA, reproduce asexually by budding/binary fission, different composition of cell, classification of member in each group difficult due to a lack of “easy” characteristics

bacteria

rna polymerase has 5 subunits, has peptidoglycan cell wall, has formal methylene, prokaryotes- binary fission, singular piece of circular dna, wide species diversity

archaea

rna polymerase has 13 subunits (more similar to eukaryotes), has regular methylene, have histones

histones

DNA is linear, so double helix is ling linear strand and wrapped around a spool, histones are proteins blocks that act as spooler to wrap up DNA, coil of blocked gets coiled again,

mitochondrial DNA

mitochondria have own DNA, singular strand of DNA

extremophiles

archaea, live in extreme environments like methan eor high slat or high temps

bacteria

have own domain, reproduce by binary fission, have peptidoglycan, antibiotics taregt singular strand of DNA as chromosome, bacteria shown zoomed 14000x of pin

gram stain negative

red

gram stain positive

purple, two layers of cell wall on outside of envelope, have peptioglycan

coccus

berries, round bacteria

bacillus

staff, rod shaped bacteria

spiral

various sprial shaped bacteria

staphylo

cluster of bacteria

strepo

twisted chain of bacteria

staphylococcus

cluster of round bacteria

what percent of human illness is caused by bacteria

50%

how many minutes does it take for bacteria to reproduce

20 minutes

how much bacteria can be reproduced in 10 hours

3 (1 hour/20 minutes) x 10 (hours) = 30, 2^30, over one billion

endotoxins

outer membrane of gram negative bacteria, less toxic, cannot be converted to toxoids

exotoxin

outside, substance secreted by bacteria cell (gram neg and pos), effective because of secretion, highly toxic, conevrted to toxoids

clostridium tetani

tetatnus, exotoxin affects any of muscles and causes them to contract,

potent

one gram of exotoxin from “clostridium botulinum” (botulism), potemt enough to kill 1,000,000 people, one one millionth of gram is lethal dose for human, secretion

botulism

anaerobic, type of food poisoning, outbreaks occur across world, botox is botulism, clostridium tetani can cause gastorintestinal probelm, orange juice thanksgiving, moldy mac and cheese

botox

destroys terminal point of axon, destroyed connection between 2 neurons, it can repair bc only junction broken, so grows a new junction, blocked in synaptic cleft, axon can fire to next neuron again after repair- takes about 6 months, botox is temporary, number 1 side effect is spontaneous death if not applied correctly

what does botox do

neurotoxin, destroy a part of a nerve

endospore formation

can withstand extreme conditions- dehydrates itself into dried endospore piece to protect itself, can survive for centuries

peptidoglycan

bacterial cell wall construction protein, vital component of bacterial cell wall, plant and animal cells do not have this, many antibiotics inhibit peptidoglycan, ex. penicillin, stops bacterial growth, immune system kicks off bacteria, protein- gram positive cell wall on outer surface purple, gram negative cell wall sandwiches between layers red, both have it

nitrogen fixation

nitrogen is major component of air we breath, N2, not biologically available, breath a lot in but don't process any of it, bacteria are able to form ammonia from N2, reduced N2 to NH3, N fixation is anaerobic, NH3 is biologically available, DNA amino acids, proteins, etc all use nitrogen

bacterial pathogens

health threats (only bacteria not archea, pathogenic responsible for botulism, bubonic plague, lyme diease, diphtheria, strep, tetanus, etc

MRSA

methicillin resistant staphylococcus aureus, has one gene on its chromosome which made it resistant that is sometimes present, few antibiotics that work on it

lyme diease

spirochete bacterium pathogen borrelia burgdorferi, willy burgdorfer discovered, secondary species- borrelia mayonii, causes way worse symptoms, can be treated doxycycline antibiotics, morality 0, tick agitates your tissues to pour blood and spits in you to keep blood pooled, bacteria goes inside and keeps reproducing, bullseye rash is symptom, 3 species of deer tick

reservoir

white footed mouse (peromyscus), houses the infection or borrelia

protista

not a monophyletic group, problem, a loose paraphyletic assemblage of ancient eukaryote lineages, unicellular, colonial, or weakly multicellular, many of unicellular lineages have complex structures and complex life histories, probable ancestors of plants (green algae), and animals and fungi (flaggellate), if not sure what it is its a protista

diplomonads

highly reduced mitochondria, common human parasite, giardia lamblia- causes beaver fever, Gi disease, coats small intestine, prevents nutrient absorption, fecal oral transmission,  zoonotic- animal sources

kinetoplastids

single large mitochondrion with DNA mass called "kinetoplast"

trypanosoma brucei

sleeping sickness, fatal neurological disease, sub-Saharan Africa, vestor- tsetse fly ( glossina sp), surface covered in millions of copies of single protein, next generation produces a different protein, clocked immune response

trypanosoma cruzi

chagasdisease, acute/chronic, vector- kissing bug (triatomatids=hemiptera), spread to southern US states, punctures to get to blood and deficate, parasite has direct entry point into system, have vector in US, not pathogen, but pathogen is traveling to US

apicomplexa

obligate parasites, plasmodium species cause malaria ~1,000,000 deaths/year, apical complex- sepcialized cells, advantage on penetrating host tissues, complex life cycles- sexual and asexual, need a mammal and insect host, insect host ins anopheles sp, DDT to kill mosquitoes, drugs to kill plasmodium, problem- resistance in both, vaccines- difficult to develop because they dont have a fixed structure, most life stages inside cells

malaria

"bad air", initially people thought it was caused by breathing bad air near swamps, mosquitos, swamp dwellers

plasmodium life cycle

5 species can cause malaria (plasmodium malarie (more mild), plasmodium falciparium (deadly) , plasmodium ovalie, plasmodium vivax, and plasmodium knowlesi), also bird and reptile and other malaria, mosquito bites injects sporozoites, go to liver, liver cells carry merozoites, go into RBCs and they burst so they can no longer carry oxygen, go into gametes and meiosis and forms new sporozoites

what mosquitoes bite

only females bite, males are vegetarian