Viruses

virus

acellular infectious particles, obligate intracellular parasites

some viruses have

a narrow host range or multiplehost species

animal virus

virus that infects eukaryotes (animals, humans, fungi)

bacteriophages

viruses that infect bacteria

virion

complete, infectious viral particle and genetic term for microbe

core

contains genetic material, nucleic acids so matrix enzymes

outer coat

capsid, envelope, attachment proteins/spikes

viral genome composition

DNA or RNA, single of double stranded

viral genome function

information to make new virions

matrix enzymes composition

viral enzymes carried in viral core

matrix enzymes function

roles in multiplication, benefit- higher spontaneour mutation rates

viral capsid composition

all viruses, protein coat

viral capsid function

protect viral genome from damage when outside host cell

viral envelope composition

some viruses, outermost layer

viral envelope function

role in entry and exit from host cell, “stolen clothing”

attachment proteins/spikes

outermost layer of virion

attachment protein/spike function

specific binding to host cell

helical naked virus

capsid envelop genetic information, particle with DNA on it

variola virus

2 lipid bilayers, animal virus

animal virus multiplication

attachment to host cell, penetration, uncoating, synthesis, assembly, release

penetration

virus entry into host cell cytoplasm

penetration by endocytosis

drawn into the cell, they come in

penetration by fusion

viral envelope combines with host cells membrane

uncoating

viral genome freed from capsid

synthesis

replication of viral components by hist cell and viral matrix

assembly

viral genome packaged into capsids and attachment proteins in capsid or cell membrane

release by lysis

burst host cell, kills host cell

release by budding

slowly kills cell, hosts cells membrane wrapped forming envelope

retrovirus

enveloped RNA viruses retro multiplication

provirus formation

viral RNA genome converted into DNA then inserted into host cell

latency

inactive state

provirus

permanent infections in host cell

types of viral infections

persistent infections, latent infections, chronic infections

acute viral infections

virus enters host and multiplies, symptoms occur

signs

objective evidence of disease, sneezing, coughing

symptoms

subjective evidence of disease, reported by patient to doctor, headache, pain, sore throat

latent virus

enters, sings occur, destroys most virus

virus permanently infect

host cell

chronic HIV

virus enters host and multiplies symptoms, doesn’t kill all but PERMANENTLY infects host

asymptomatic

no symptoms present and no signs

oncogenic viruses

increase a patient risk of cancer developing

macromolecules

organic compounds contain both hydrogen and carbon

prion

proteinaceous infectious particle that lacks genetic material

transmissible

transfer throughout brain