Cell Structure Flashcards
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are prions and viruses living?
no, they’re biologically active
what are the three different ways that proteins may occur?
heredity: genetic
Acquired: infectious/latrogenic
Sporadic: unknown cause, no known risk factors
why is it really difficult to denature prions?
because they’re heat shock proteins
what is the composition of a virus
- contain genetic material that may be either DNA or RNA
- don’t have a cell membrane or internal metabolic activity (no cytoplasm
how are viruses cateogirzed
by the type of genetic material they contain
is viral genetic material enclosed?
yes. in a protein capsid and may or may not have an outer lipid/protein envelope
do viruses have a life cycle? why or why not
no because they don’t have a cell structure and aren’t living organisms
what do viruses require in order to carry out their replication?
living cells
no metabolism means…
no process to interrupt with antibiotics. ex: viruses
what occurs in all infected cells? What occurs in some?
they all have a lytic cycle.
Some have a lysogenic component
Given an example of an infection that has both a lytic and lysogenic cycle
Chicken pox. Shingles
List the basic steps of the virus replication/infectious cycle
- absorption (has to recognize receptor on a target cell)
- penetration (binding tricks the cell to pull virus in and release its genetic material_
- production of early viral proteins
- replication of viral genetic material
- production of late viral proteins (capsid)
- Assembly of viral particles
- release of particles/lysis, or budding
budding
a slow leaking of the cell’s contents
lysis
when the cell bursts
**Lysogenic modification
early viral proteins insert viral DNA into host DNA and it shuts down
**Retrovirus modification
reverse transcriptase produces viral DNA from viral RNA template
true or false: All lysogenic cells have DNA
false. an exception is retroviruses which have RNA (HIV).
Which viruses have DNA?
adenoviruses, HPV, herpes simplex, epstein barr, and varicella zoster (shingles)
which viruses have RNA
rubella, influenza, ebola, COVID, HIV
list the lytic DNA viruses
adenoviruses
List the lysogenic DNA viruses
HPV, Herpes simplex, Epstein barr, varicella zoster
List the RNA lytic viruses
rubella, influenza, ebola, and COVID
list the RNA lysogenic viruses
HIV
