chapter 9/13(diana's version) Flashcards
not cells on their own (acellular, needs a host cell in order to replicate)
virus
true or false, virus causes propogation?
true
what does intracellular parasites mean, in terms of viruses?
it means, that one suffers and the other benefits, in this cases the virus benefits rathe than the human (host), since it can cause disease in us.
name the virus features:
filterable disease causing agents(meaning they exist)
acellular : do not have a plasma membrane
contain single type of nucleic acid : either RNA or DNA (never both)
surrounded by a protein coat called capsid
may or may not additional envelope of lipids or and proteins
what is swine influenza?
pig influenza
what is avian influenza?
bird influenza
Influenza A virus?
human influenza
viruses can infect animals, plants , fungi, protozoa and bacteria. Therefore they can create_______
they can create pandemic because they are able to cause disease with different type of hosts (impossible to get rid of all of them)
Host range:
TO be able to infect a cell the virus must recognize particular features on the host cell surface:
name an example
HIV recognizes a specific receptor CD4 on human immune cells
name the structure of a virus
1) single nucleotide
2) capsid
3)envelope(not all virus have this)
the genetic material can be either ____ or ______ stranded, name the possible outcome
dsDNA
ssDNA
dsRNA
ssRNA
human is always linear and double stranded is that true?
that is true
capsid : name the characteristics
protein coat surrounding the nucleic acid
made up of individual proteins called capsomeres
provides the virus with its shape
the capsomere arrangement its characteristics of a particular virus
nucleocapsid: is the nucleic acid and the capsid together
does shape matter in virus?
it does not matter, only in identification but no overall it does not matter
does every single virus have a capsid?
yes, they do have a capsid.
diseases that are caused by viruses with an envelope, has a protective outer layer that surrounds the virus?
this is in fact true, they have an external coating surrounding the nucleocapsid
viruses are either:
non envelope/naked virus
enveloped
the spikes are attach right onto the nucleocapsid
this would be identified to as naked virus
often when we talk about the shape of the capsid, it often will determine the shape of the what virus?
naked virus
HIV nucleic acid (shape of enveloped) however, when you really distinguish its shape, the morphology of this is a
conical
complex viruses
are complicated structure
may have more proteins structures attach to the capsid
this is the most common in bacteriophages which are viruses that infect bacteria
recall that bacteriophage will always infect what?
it will always infect a prokaryotic cells
Capsid
DNA
Sheath
Pin Baselate
Tail fiber
A-T even bacteriophage
written above is the structure of a complex virus, are they all getting being included?
no, nucleic acid is really just the one needed (more of the head) , it does not insert the whole thing because it simply does not have any room for them.
classification of viruses are based on differences : name those difference
- Nucleic acid type
2.Presence of envleope
3.Capsid structure
Is this true or fale:
The presence or absence of an envelope affects how viruses interact with their host cells, as well as their resistance to environmental conditions such as heat, chemicals, and radiation. Enveloped viruses tend to be more fragile and sensitive to these factors compared to naked viruses.
True
viruses that last longer on surfaces when you treat them with disinfectant
naked viruses
what example would this be ?
retroviridae
family
what example would this be
lentivirus
genus
HIV can be considered ________
it can be considered as a pandemic, as many people are contracting them these days. Why, because its slow and for ex: a person with HIV can live for about 23 years or more.
Most lentiviral vectors are based on the Human Immunodeficiency Virus (HIV): true or false.
that is true
name this description :
(attachment to the host cell)
Spike going into the host cell (this happens in envelope and naked virus) just depends since envelope has the spikes on the external naked has it on their protein coat
and in the best of your knowledge, describe what is going on in this factor
adsorption
attachment to the host cell
virus have attatchment site: recognizes protein or glycoprotein of host cell membrane.
name this description :
naked viruses must enter by endocytosis
penetration
there are two ways envelope can enter the host cell, what are they?
1) enter via endocytosis
2) enter by fusion
what do you figure the quantity would be when it enters by fusion and endocytosis?
the quantity would be bigger
what virus will keep the cell alive and making more virus (get released shortly)- can get into naive cells (make more symptoms more severe) and infected as well
this would be called an envelope virus
true or false. One of the fundamentalism of creating an infection is getting the nucleic acid inside the cell?
that is indeed true
what’s capsid protein called?
it is called the capsomeres
Multiplication of viruses:
1) spike protein
2) capsomeres to make capsid
3)nucleic acids
now that we have the rewuirement we need to do : what is the next step to do?
maturation and assembly
briefly describe what maturation and assembly mean, briefly
new virus particles are assembled from nucleic acids and capsomeres
and nucleocapsids are formed
describe this description:
contains spike proteins to bud out’exit’
” do it again and again until it kills itself”
host cell remains alive for a long time
this would be an envelope release, the envelope forms the plasma membrane
steady and release of mature enveloped viruses over time
host cell remains alive for a long time
what are the two types of infection
1) acute infections
2) persistent infections
persistent infections are divided into four subgroups, what are they
1) acute infection followed by late complications
2) chronic infection
3)slow infection
4)latent infection
measles can go to cause subacute sclerosing pan-encephalitis
true
slow viral infections:
after initial infection the amount of virus present increases over a long period of time
the initial infection is followed by asymptomatic period
eventually a slow, and progressive disease results: HIV
- HIV can be transmitted at any point following initiation infection
HIV enetually develops in AIDS
Viruses and cancer:
viral dna can transform normal animal cells into malignant cancer
-only certain viruses have this capbaility
-oncogenes
- animals cells have normal genes called proto-oncogenes
-when mutations occur in these genes they become oncogenes
this results in an uncontrolled cell growth which leads to tumor formation
the mutation can occur as a result of mutagens (carcinogens)
true or false:
oncogenic viruses :
viral dna is inserted into host cell chromosomes
this is true
there may not be oncogenes present in the viral DNA ?
false
oncogenic viruses can also ause proto-oncogenes to be over expressed which leads to translation
and this over expression results in the proto oncogene becoming an oncogene
false, it would lead to transcription
how a single protein can be infectious?
We have a gene that makes this protein called NP
Normal protein
this protein normally does not do harm = protein has no known function
infected animals have teh same protein but dif form
Prion protein
This PP can convert NP into a prion protein shape
eventually all np are
converted into the PP shape
this results in disease
when you have chicken pox, is it actually clearly gone, or is it still there, just ‘sleeping’?
when you have chicken, IT IS NEVER TRULY gone, in other words ‘sleeping’ might be another term to describe it,may be reactivated years later to shingles
describe what this means:
this type of infection is usually very brief, in terms of duration, and the symptoms depends on your immune system
this is known as a acute infection
you have to kill virus that are replicating (however you have to be very careful) that you do not take any drugs that will clear the good virus***
just a fact, not a question
true or false.
chemotheraphy is really toxic in other words (it doesnt know what cells to kill and what not to kill)
true
this is envelope virus, and long period of time (after the acute period)—> potentially forever, how it’ll stay depends on your body
persistent viral infections
true or false.
not every chronic infection has is asymptomatic or symptomatic.
true
describe what this means:
this looks like it’s gone but it is NOT GONE gone:
this is known as acute infection with late complications
we start here (was never there before) get some control, if you don’t eliminate what is it called:
this is called persistent
describe what this means:
stay relatively high but lower than acute (but still relatively high) always at detectible level, disease may or may not be present
chronic infections
describe what cirrhoris mean?
is a liver disease, people who consume a lot of alcohol could be at risk as well
describe what this means? in terms of infections
gradually creeps up
slow viral infections
describe what rapid progressor vs. Long term non-progressor
rapid progressor= became aggressively HIV affector, developing aids in much shorter year
long term progressor- takes more than 10 years to reach AIDS = fatal outcomes
why are they different when the same virus is affecting them for long term non progressor, rapid progressor
it depends on your immune system
DESCRIBE WHAT THIS MEANS:
this is undetectable (but this reactivate in any single time )
this is poorly understood, associated with _______ reactiviting = immunocompromised
latent viral infections
DNA virus “transformation” can actually cause what?
can cause cancer
what type of genes to we have that WE CANNOT ABUSE, or it will cause tumor or cancer
protooncogenes
what does protooncogenes, and oncogenes stand for?
proto- before
onco- cancer
proto oncogenes- can lead into cancer
onco- cancer
genic/genes= produce
is carcinogen a chemical?
yes it is a chemical
Human papilloma virus causes what, and define what it is?
a wart, and it is a tumor (belign tumor )
produces very similar to strep throat
this is known as epstein-barr virus
may cause nasopharyngeal cancer (ultimately B-cell cancer)
epstein barr virus
these are not virus(but they are kinda like virus)
-they are molecules and infectious agents
-RNA make you sick
none that infect human
viroids
brains starts to form sponge form in the brain this is called
prions
sponge like holes in brain tissue can result in a disease called a
transmissible spongiform encephalopathy
prions are resistant? and why are they not easily destroyed by high temperature?
yes they are resistant, and they are not easily destroyed because they are already unfolded
As we know, virus have a very few of their own enzymes, is it because they’re ONLY gonna bring things they wants, that the cell does not ?
yes this is indeed true
where is the spikes located?
lcoated inside the envelope
what does spikes determine?
they determine which cell to enter to
can never create a long lasting infectious (kill the bateria) what type of virus is this?
naked virus
for persistent viral infections, we are aware that virus particles are continously present in the body, where is this coming from?
released from infected cells by budding
true or false. Persistent infection may or may not cause disease
this statement is true
capsid+ nucleic acids =
virus
Most frequently prions are carried in ____
Sheep infected with prions is called ___
The infected sheep is eaten by cows and the cow develops _____
The cow is eaten by humans and the human develops _______
food
scrapie
mad cow disease
variant creutzfeld-jakob disease
this step makes use primarily of host metabolic enzymes , and both dna and rna virus have the viral proteins synthesized in the cytoplasm as well, capsomeres are constructed.
biosynthesis
