Exam 2: Cell Structure Flashcards
Cell theory
to be considered alive, an organism must have cell structure
cell structure
- genetic information (DNA)
- plasma membrane (separates internal and external environments; maintains internal environment)
- cytoplasm (internal environment, carries out metabolic activities )
If something is not living will antibiotics have an effect on it?
examples of things antibiotics do not work on
no
prions and viruses
complex molecules that can affect cell activity can be confused with living organisms. But they lack some or all requirements for ______
cell structure
prion
infectious protein with no cellular components
- can not make antibiotics against them
3 ways prions can occur
- hereditary - genetic
- acquired - infectious/iatrogenic
- sporadic - unknown case, no known risk factors
Why is it so hard to denature prions?
they are heat shock proteins
Viruses
- contain DNA or RNA
- do NOT have a cell membrane or internal metabolic activity
- categorized by type of genetic material they contain
In a virus how is genetic material contained?
in a protein capsid and may have an outer lipid/protein envelope
Do viruses have a life cycle?
no
Viruses do not have metabolism so…
no process to interrupt with antibiotics
What do viruses need in order to carry out replication?
living cells
Cycles that occur in infected cells all have a______ som have a _____
lytic cycle
lysogenic component
lysogenic component
produce viral proteins that insert viral material into the host material to stay there until it comes to go into the lytic stage
chicken pox replication
- get directly lytic
- some peripheral nerve cells will go lysogenic years later and you can get a virus going from lysogenic to lytic and that is when you would get shingles
- you can follow line of the peripheral nerve that has the outbreak, not all over the skin
- can have many outbreaks of shingles
Basic steps to virus replication/infectious cycle
adsorption penetration production of early viral proteins replication of viral genetic material production of late viral proteins assembly of viral particles release of particles/lyse or budding
Lysogenic modification
early viral proteins insert viral DNA into host DNA and shuts down
Retrovirus modification
reverse transcriptase produces viral DNA from viral RNA template
like with HIV
adsorption
it has to stick
it recognizes a receptor on a target cell, has spike proteins
binding tricks cell into penetration
penetration
get release of genetic material
budding vs lyse
budding - little pieces break off like a slow leak
lyse - complete burst
Lytic DNA viruses
adenoviruses
