Viral characteristic
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
---|---|---|---|---|---|
Unique properties of viruses | Either DNA or RNA, strict intracellular parasite, replicates in host cell, uses host cell to replicate nucleic acid.
🗑
|
||||
viral structure | nucleic acid surrounded by capsid and possibly a lipid or polysaccharide envelope
🗑
|
||||
capsid | protein shell around nucleic acid
🗑
|
||||
nucleocapsid | nucleic acid + capsid
🗑
|
||||
capsomere | structural unit of capsid
🗑
|
||||
envelope | lipid membrane around nucleocapsid in some viruses- stolen from host cell, factor of antigenicity
🗑
|
||||
vorion | complete viral particle
🗑
|
||||
Charactoristics used to classify viruses | DNA or RNA, ss or ds, size and shape of virus, envelope, host cell infected, disease produced
🗑
|
||||
prion | proteinatious infectious particle, replicate through conversion of other host proteins
🗑
|
||||
diseases caused by prions | Scrapie, Kuru, CJD, BSE bovine spongiform encephalitis (mad cow)
🗑
|
||||
Major steps in viral replication | attachment, penetration, uncoating, biosynthesis, morphogenesis, release
🗑
|
||||
Herpes simplex virus type 1 (HSV1) | Fever blisters- infect nervous tissue
🗑
|
||||
Herpes simplex virus type 2 (HSV2) | genital area- infect nervous tissue
🗑
|
||||
Cytomegalovirus (CMV) | found in the lymphotropic- lympatatic system
🗑
|
||||
Epstein-Barr virus (EBV) | found in the lymphotropic- lympatatic system
🗑
|
||||
Overall Structure double-stranded DNA genome | encodes for 60-120 genes- 1 copy- linear
🗑
|
||||
icosahedralcapsid: | 5 diff. proteins
🗑
|
||||
tegument: | enclosed a group of protein tha are needed for early infection, they are going to start the replication process. They help turn off the functions
🗑
|
||||
Envelope | Viral derives proteins host derived photolipids
🗑
|
||||
Infection cycle 1.Binding | invalue viral glycoproteins (gc,gd) Envelope going to search for specific receptors on the host cell
🗑
|
||||
RNA transcription/DNA replication In the nucleus: viral DNA can either circularizeddue to cellular DNA repair enzymes circularized state: | the virus becomes latent
🗑
|
||||
In the nucleus: viral DNA can either circularizeddue to cellular DNA repair enzymes or it can remain linearthrough the action of the immediate-early ICP0 protein, which inhibits cellular DNA repair. linear state: | a productive replication cycle begins
🗑
|
||||
Two main phases of transcription •Early: ____________________________________________ •Late: ____________________________________________ | transcription that occures before DNA replicates
🗑
|
||||
Two main phases of transcription ____________________________________________ •Late: ____________________________________________ | transcription that occures during DNA replication
🗑
|
||||
Early transcription Immediately early genes | set of 5
🗑
|
||||
Early transcription Immediately early genes | MRNA is formed in the nucleus, they are primed by the tegament proteins
🗑
|
||||
Early transcription Immediately early genes | MRNA will leave nucleus and enter cytoplasma looking for ribosomes immediate early proteins go back into lucleus- they they will prime the next round of transcription.
🗑
|
||||
Early transcription Delayed early genes | 12 geans are needed for the next process structual proteins and replicate DNA
🗑
|
||||
Early transcription Late transcription | Structural proteins are being made- host shut down - capsid protein - envelope proteins Start DNA replication Early transcription ends.
🗑
|
||||
all Herpesvirusescan establish latencyin the body after primary infection | Latency = virus is dormant in cell
🗑
|
||||
Latent herpes viral genome (DNA) may be | circular form inside host cell No treatment to prevent establishment of latent infections. Nor will remove altent virus
🗑
|
||||
Latency occurs within specific nerve cells –HSV-1: | trigeninal ganglia
🗑
|
||||
Latency occurs within specific nerve cells ––HSV-2: | Sciatic nerve gangha
🗑
|
||||
HSV-1 and HSV-2: are not systemic illnesses | will only be infecting one part of your body
🗑
|
||||
systemic illnesses | systemic a pathogen able to infect the whole body like to hide inside the cells and avoid the host immune system.
🗑
|
||||
Transmission of HSV1 | oral to aral
🗑
|
||||
HSV1 virus multiplies | in the epithelia cell of the mouth, throat, face - result distrys some cells
🗑
|
||||
Cells often fuse together producing | multinuncleated giant cells
🗑
|
||||
Blisters develop at the inoculation site | coldsores-fever blisters saliva and cells secretions contain the virus particle
🗑
|
||||
Transmission of HSV2 | spread via break in skin or mucus membranes- most often throu sexual contact will end up having blisters on the external genitalia
🗑
|
||||
HSV2 blister form | large multinucleated cells- can have upto 50,000-200,000 virus per cell
🗑
|
||||
HSV2 incubation time | 1 week- shedding host cell lyse to reveal virus
🗑
|
||||
HSV2 replication | virus will use host machinary to replicate viruses- Shuts down the host matabolism.
🗑
|
||||
What are the two enzymes that virus makes | Viral thymidine kinase DNA polymerase
🗑
|
||||
Viral thymidine kinase | provide substrates for replication of viral genome
🗑
|
||||
DNA polymerase | diff. from the cellular DNA polymerase in subtrate specificity
🗑
|
||||
most effective drug agains HSV | Acyclovir (zovirax)
🗑
|
||||
Herpes thymidine kinase | add a phosphate group to acyclovir
🗑
|
||||
Cellular enzymes | kinases adds 2 phosphate groups
🗑
|
||||
Acyclovir has two mechanisms of action Mechanissm 1 | acyclovir triphosphate bond to viral DNA- inactivates
🗑
|
||||
Acyclovir has two mechanisms of action Mechanissm 2 | acyclovir triphosphate incorporated in the newly synthesized virus DNA- stops viral replication
🗑
|
||||
varicella | chicken pox
🗑
|
||||
Zoster | shingles
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
kmaemom
Popular Laboratory Science sets