Lecture 10 Viruses General Characteristics Flashcards
What type of genetic information are in viruses?
DNA or RNA
What is the genetic information in viruses contained in?
Protective protein coat
Inert particles
no metabolism, replication, motility
Genome hijacks host cell’s _____
replication machinery
Are viruses organisms?
No
What do viruses require?
live organism as host
Can viruses be grown in pure culture?
No
Which microscope are viruses NOT seen in
Light microscopy
Viruses that infect bacteria are called
bacteriophages
viruses are vehicles for what
horizontal gene transfer
what is virion
nucleic acid
What is virion surrounded by
capsid (protein coat)
Capsid is composed of what
Capsomeres
What are nucleocapsid
Capsid plus nucleic acids
What is nucleic acid
Either DNA or RNA, may be singular stranded or double stranded
_____ viruses are surrounded by lipid bilayer obtained from host cell
Enveloped
Enveloped viruses are surrounded by what layer
Lipid bilayer obtained from host cell
_____ is between nucleocapsid envelope
Matrix protein
How is non-enveloped viruses different from enveloped viruses?
More resistant to disinfectants
_____ are attached to receptor sites on host cells
Spikes
Phages attach by _____
Tail fibers
Spikes attach to _____ sites on host cells
Receptor
What are the three shapes of viruses
Icosahedral, helical, complex
What is an example of icosahedral
20 flat triangles
What is an example of helical
Capsomeres arranged in helix
What is example of complex
phage, icosahedral nuceleocapsid, helical protein
What type of virus is papillomaviridae
type of DNA, outer covering
double stranded DNA, non-enveloped
disease= human papillomavirus
What type of virus is herpesviridae
type of DNA, outer covering
Double stranded DNA, enveloped
disease=herpes zoster virus, herpes simplex virus
What type of virus is Reoviridae
type of DNA, outer covering
double stranded, non-enveloped, human rotavirus
What type of virus is Picornaviridae
type of DNA, outer covering
Single stranded (plus strand), non-enveloped
poliovirus, rhinovirus, hepatitis A
What type of virus is Caliciviridae
type of DNA, outer covering
Single stranded (plus strand), non-enveloped, norovirus
What type of virus is coronaviridae
type of DNA, outer covering
single stranded (plus strand), enveloped
SARS, MERS
What type of virus is Rhabdovirus
type of DNA, outer covering
single stranded (minus strand), enveloped, rabies
What type of virus is Paramyxoviridae
type of DNA, outer covering
Single stranded (minus strand), enveloped, influenza virus
What type of virus is hepadnaviridae
type of DNA, outer covering
DNA, enveloped, hepatitis B
What type of virus is Retrovirus
type of DNA, outer covering
RNA, enveloped, human immunodeficiency virus (AIDS)
What are viruses that are oral-fecal route called
Enteric viruses
What are respiratory route called
Respiratory virus
what is arboviruses
spread by arthropods, often can infect widely different speices
What are the three types of bacteriophages
Lytic, temperate, filamentous
What is latent state
Viral genome remains silent, but is replicated along the host cell genome
What is productive infection
New viral particles produced
Lytic phages exit the host by _________ the cell
Lysing
What type of infection is lytic phages
Productive infection
What are the 5 steps of lytic phase
Attachment
genome entry
synthesis
assembly
release
What happens in attachment phase of lytic phage
phage attaches to receptors
What happens in genome entry phase of lytic phage
T4 lysoszyme degrades cell wall, tail contracts, injects though cell wall, capsid remains OUTSIDE cell
What happens in synthesis phase of lytic phage?
Synthesis of phage proteins and genome