High Yield Biology Flashcards
(136 cards)
What are viruses made up of?
Genetic Material
Protein Coat
Sometimes, an envelope containing lipids
Protein coat of a virus is called
Capsid
Are enveloped viruses easier or harder to kill than non-enveloped and why?
Easier because the envelope is sensitive to heat, detergent, and desiccation
Why are viruses considered obligate intracellular parasites?
Because they cannot reproduce on their own
What are virions?
Viral progeny that are released to infect additional cells
Bacteriophages are?
Viruses that specifically target bacteria
What additional structures does a bacteriophage have?
Tail sheath - syringe to inject genetic material
Tail fiber - recognize and connect to host cell
Positive sense viral information?
Single stranded RNA virus who’s genome can be directly translated to functional proteins
Negative sense viral information?
Single stranded RNA virus who’s genome must be synthesized by RNA replicase into a complementary strand which can then be translated into a functional protein
What additional thing must a negative sense RNA virus contain?
RNA replicase
Retrovirus life cycle
Single stranded RNA virus that contains reverse transcriptase which synthesizes DNA from the RNA strand and the DNA is then integrated into host cell’s immune system
What additional thing must a retrovirus contain?
Reverse transcriptase
Productive virus life cycle
Keeps the host cell alive and virus leaves through extrusion - virus can keep using cell machinery
Lytic cycle
Bacteriophage reproduces and fills cell with virions and then the cell lyses and other bacteria are infected
Virulent Viruses
In lytic cycle
Lysogenic cycle
Virus integrates into the host genome and is replicated as the bacteria reproduces
Provirus
In lysogenic cycle
Prophage
In lysogenic cycle
What are prions?
Infectious proteins
Are prions living things?
No
How do prions cause disease?
Trigger the misfolding of other proteins - for example, conversion of alpha-helix to beta-sheet
What are viroids?
Small pathogens of a short circular single-stranded RNA that infect mostly plants
How do viroids cause disease?
Bind to a large number of RNA sequences to silence genome - results in metabolic and structural damage
How many cells are prokaryotic organisms?
Single-celled