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
