Viro - Lecture 1

drraythe's version from 2015-08-30 15:35


Question Answer
What is the resolution of a light microscope?0.3 micrometers(μm) (not large enough to see a virus)
What is the resolution of an electron microscope?2 nm
Viruses are ___microscopic infectious agents that are ___ while outside the host. Therefore, they are obligated to ___ in order to multiplySub, inert, Parasitize cells
What is a viral capsid? What is it composed of?It's a protein shell to protect the nucleic acid (NOT THE ENVELOPE). It's made of subunits called capsomeres
What is a capsomere?A subunit of a viral capsid (protein shell-- NOT THE ENVELOPE)
Explain a viral envelope (origin, contents)A lipid bilayer surrounding the virus which is DERIVED FROM THE HOST CELL. It contains proteins from the virus, though. SOME have peplomers (large projections)
What is a peplomer?A large projection from a viral envelope
Explain how having an envelope can affect a virus in its environment/ interaction w/ disinfectants.If they HAVE an envelope, they are MORE sensitive to disinfectants & LESS able to live out in the environment. (Think of hot lipids melting in the sun)
What’s the basic difference she said about the difference between segmented & nonsegmented genomes?Segmented ones evolve faster (ex= the flu) (think about a bunch of little segments being easier to rearrange)
What does -viridae mean, as opposed to -virus?-viridae= family
–virus = genus or species
What are the DNA virus families?(9) Circoviridae, Parvoviridae, Hepadnaviridae, Papovaviridae, Adenoviridae, Herpesviridae, Asfaviridae, Iridoviridae, Poxviridae
Mnemonic to remember which virus families are DNA viruses?If I saw an IRIDescent POX on your AS(fa), I'd think you had HERPES. I'd do a half CIRCle away from you & say "my liver (HEPA) already has PARVO! & my PAP wont like you..." I AD(eno)ed.
Which DNA viruses are the smallest?Circo & Parvo -viridae are super small! (The SMALLEST CIRCLE is still a PARt not to be ignored)
Are DNA viruses usually ss or ds? Where do they usually replicate? Exceptions?Usually ds (just look at how DNA looks) & usually replicate in the nucleus (where DNA would usually be). The exceptions are SS for Circo & Parvo (theyre so small they dont get another strand) & Pox replicates in cytoplasm (too big to get in there)
What is the largest DNA virus family?Poxviridae (getting chicken Pox is a BIG pain in the butt)
Are RNA viruses usually ss or ds? Exceptions?Usually SS & exceptions (the ds ones) are: Reo & Birna. (RB= REALLY BIG - as in, double what the others have)
If a naked virus was on your fence, would you be scared?Yes! Naked = easier to live in enviro. Wouldnt you be scared if there was a naked thing on your fence?
Are RNA usually naked or enveloped? Exceptions?Usually ENVELOPED!! Exceptions (naked ones) are: Picorna, Calici, Astro, Reo, Birna (CAL PICked on RE-BIR on the ASTRO turf bc he was naked)
Are DNA usually naked or enveloped? Exceptions?Usually enveloped.....naked ones are: Circo, Parvo (super small, so dont have room), Papo, Adeno (who didnt want to think about their pap naked? I AD(eno)ed )
Where do RNA viruses usually replicate? Exceptions?In the cytoplasm! (Where RNA usually is). Exceptions are Retro & Orthomyxo. (Retro bc it has to do w/ DNA & shit, & the other is just MYXin it up)
Is it RNA or DNA viruses where we care about if theyre segmented? WHICH are segmented?RNA! segmented's are: Reo, Birna, Orthomyxo, Bunya, Arena (Reo & Birna are already exceptions for being ds. then an ARENA full of ORTHOtic BUNs would be a strange SEGMENT of reality)
Which virus families are icosahedral?(All of the DNA except POX) & then for RNAs, the three smallest (Pico, Reo, Flavi) (FRP, pic[k] Reo[l] flavors)
Which viruses are negative stranded?(Only RNAs) Orthomyxo, Bunya, Arena, Rhabdo, Filo, Paramyxo (BAR FOP is a negative thing to be called)
Circular shape viruses?Circo, Hepadna, Papo (Circos on paps liver)

Let's play "DNA, RNA, EXCEPTIONS?"

Question Answer
Circo (DNA, RNA, EXCEPTION?)DNA, super small so ss, NAKED, CIRCLE (That circle is so tiny I could only draw it w/ one single strand of hair)
Parvo (DNA, RNA, EXCEPTION?)DNA, super small so ss, NAKED
Adeno (DNA, RNA, EXCEPTION?)DNA, naked
Pox (DNA, RNA, EXCEPTION?)DNA, super large so replicates in cytoplasm
Picorna (DNA, RNA, EXCEPTION?)RNA, naked, icosahedral (Pico-chu doesn't wear clothes! he's naked! & goes in a icosahedral pokeball)
Calici (DNA, RNA, EXCEPTION?)RNA, naked (everyone is sexy & naked in cali!!)
Astro (DNA, RNA, EXCEPTION?)RNA, naked (porn STARS are naked)
Reo (DNA, RNA, EXCEPTION?)RNA, naked, ds, segmented
Birna (DNA, RNA, EXCEPTION?)RNA, naked, ds, segmented
Flavi (DNA, RNA, EXCEPTION?)RNA, icosahedral (need a special packet for all that flavor)
Orthomyxo (DNA, RNA, EXCEPTION?)RNA, segmented, NEG STRAND. RNA THAT REPLICATES IN THE NUCLEUS. (in order to mix something, it cant be one large hunk-- break it into segments! also wear a Orthotic brace so you don't hurt your wrist)
Bunya (DNA, RNA, EXCEPTION?)RNA, segmented, NEG STRAND (my ass buns are segmented by a crack that looks like a neg sign)
Arena (DNA, RNA, EXCEPTION?)RNA, segmented, NEG STRAND (a sports Arena is a negative place for me)
Filo (DNA, RNA, EXCEPTION?)RNA, NEG STRAND (Filo is neg strand, bc Flavi--flavor--is good which is positive strand)
Retro (DNA, RNA, EXCEPTION?)RNA (DIPLOID). RNA THAT REPLICATES IN THE NUCLEUS. (everything about Retros is weird. just learn that now.)

Objectives answered for lecture 1

Question Answer
Define virusViruses are submicroscopic (can only see w/ an electron microscope (2nm) not a light microscope (0.3 micrometers) ) infectious agents that are inert while outside the host. Therefore, they are obligated to Parasite cells in order to multiply
Describe the components, nature, & where it derives from of the viral particle...genomeDNA or RNA, Single stranded (ss) or double stranded (ds), Positive (+) or negative (-) sense (pos polarity-- no problem, easy to replicate. neg stranded need an extra step ), Linear or circular, Segmented or non-segmented...There are also viral nonstructural proteins that may or may not be packaged into the mature nucleocapsid
Describe the components, nature, & where it derives from of the viral particle...capsidIt’s a protein shell that protects the nucleic acid. It is composed by subunits called capsomeres. The capsid may also contain enzymes & non-structural proteins, but there are no cell organelles (ribosomes, etc). Its symmetry can be icosahedral, helical or complex
Describe the components, nature, & where it derives from of the viral particle...envelopeThe envelope, a lipid bilayer, is derived from the host cell in a process called budding. It contains proteins from the virus (ex. receptors). Some families have peplomers (large projections). Enveloped viruses are more sensitive to disinfectants & less resistant in the environment (this influences their mode of transmission)
List the types of symmetryIcosahedral, helical or complex
Define the concept of capsomereA capsomere is the subunit that together composes the capsid, which is the protein coat around the virus DNA.
Define the concept of peplomerA peplomere is large projections off the viral envelope.
Define the concept of epitopeAn epitope, also known as anti-genic determinant, is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. For example, the epitope is the specific piece of the antigen that an antibody binds to
Identify & differentiate the types of viral genomesDNA, RNA, DS, SS, linear, circular, + or – sense, segmented or not
Describe the concept of + & – sensePositive sense is 5' to 3' & it is able to be directly translated into viral proteins. Negative sense is 3' to 5' & cannot be translated into protein directly. Instead, it must first be transcribed into a positive-sense RNA that acts as an mRNA
Identify who determines how to classify a virus, what is the suffix for every categoryViral taxonomy is determined by the International Committee on Taxonomy of Viruses (ICTV). The suffix for every category is.... Order (-virales) Family (-viridae) Subfamily (-viridae) Genus (-virus) Species (-virus)
Explain what the base of viral classification these days isNowadays, classification is based on 1) type of genome, 2) strategy of replication 3) structure of the virion
Compare & contrast RNA from DNA viral families.DNA is mostly DS, half are enveloped, most REPLICATE IN NUCLEUS (exception of Pox). RNA is mostly SS, most are enveloped, most are non-segmented, most replicate in the cytoplasm
Distinguish large from small virusesDNA - smallest are Circo & Parvo. Largest is Pox
RNA - Pico Calici & Astro are small, Retro is so big that it's diploid! (but not DS)
Distinguish viruses which replicate in the nucleus from those which replicate in the cytoplasmMost DNA replicate in the nuc, except POX. most RNA replicate in the cytoplasm, except Orthomyxo & Retro
Distinguish the resolution of light microscopy from that of electron microscopyLight= 0.3 micrometers
Electron= 2nm
Briefly explain the functions of APHISAPHIS is The Animal & Plant Health Inspection Service (APHIS) is an agency of the United States Department of Agriculture (USDA) responsible for protecting animal health, animal welfare, & plant health. APHIS is the lead agency for collaboration w/ other agencies to protect U.S. agriculture from invasive pests & diseases.
Briefly explain the functions of the OIEThe World Organization for Animal Health is the intergovernmental organization responsible for improving animal health worldwide. It was created by an international agreement as the International Office of Epizootics