Exam 3 Ch. 6 Flashcards
(34 cards)
Virus
- Infectious agent w/ simple acellular organization
- No metabolism
- Reproduce only w/in living host cell
- Size 10-400 nm
- Infect animals, plants, fungi, Archea, bacteria
Virology
Study of viruses & other acellular agents
Viruses have no ___
Metabolism
Nucleocapsid
Protein coat + nucleic acid
___ ____ encodes for protein coat
Nucleic acid
Capsid
- Protective protein coat
- Aids in transfer of Nucleic Acid b/w host cells
- Sub unit is capsomer which self assembles
Spikes
Proteins projecting from envelope often used for attachment or release from host cell, some are enzymes
Enveloped virus
Virus w/ a membrane surrounding nucleocapsid
Non-enveloped/ Naked Virus
No envelope!
Virion
Complete virus particle
Bacteriophage
Virus that infects bacteria
Plus/positive strand RNA
RNA genome identical to mRNA
Minus/ negative strand RNA/ DNA
Genome complementary to mRNA
Steps of Viral Multiplication
- Adsorption
- Entry into host cell
- Synthesis
- Assembly
- Release
Adsorption
Receptors on host cell bind to molecules on surface of vision
Entry into host cell
Fusion w/ host cell membrane or by endocytosis or injection of nucleic acid
Synthesis
Production of virus parts by host cell
____ ____ usually take over host cell
Early proteins
____ ____ usually responsible for capsid protein production, self assembly & release
Late proteins
Assembly
Put together vision particles either in nucleus or cytoplasm
Release
Budding or lysis of host cell
Virulent phage
Immediately takes over host cell followed by release from host cell by lysis
Temperate phage
Can either immediately take over & Lyse host cell or can remain in host cell w/out destroying it
Lytic
Take over host cell & lyse