micro d1

final preparation

virus

infectious particles that pass through bacterial filters

genome, capsid, envelope

viral anatomy

capsid

protein coat surrounding the genome

envelope

made of phospholipid bilayer - called envelope viruses

\-membrane that surrounds the capsid

\-has vital proteins (spikes) and host proteins

nucleocapsid

some viruses only have capsid and nucleic acid

virion

non-cellular microbe that has taken over host cell

virion

non-cellular microbe that has taken over host cell

obligate parasites

viruses are …… …… and are incapable of growth without a host

virulent

kill the host cell quickly, usually by lysis

temperate

may remain hidden and dormant for a very long time in their hosts

\-causes disease slowly

yes

can viruses have single or double stranded DNA or RNA

no

do viruses have ribosomes

no

do viruses have metabolism?

bacteriophage

viruses that infect bacteria

adsorption, penetration, synthesis, assembly, release

stages of the lytic cycle

bacteriophage plaques

since bacteriophages are non-motile, bacteriophages will form circular plaques in a lawn of bacteria, each plaque is formed by a single bacteriophage infecting a single bacterium

lysogenic life cycle

some bacteriophages, as an alternative to lytic growth, can “hide” in the host and lie dormant (temperate)

adsorption, penetration, integration of prophage, growth, viral induction, synthesis, assembly, release

lysogenic life cycle stages

provirus

integration into the genome

lysis

cell breaks open, releasing all virions at once

budding

virions bud off the infected cell

animal viruses

budding is specific to

cold and influenza

viral respiratory tract infections, rapidly infectious, rapidly contagious

airborne droplets

the cold and flu are transmitted by

epithelial cells in the nose, throat, and lungs

cold and flu infect

rhinovirus

“nose virus” most common cold

specific

infection grants immunity but only to that ………. cold

3

how many flu varieties are there

A

most seasonal flu type

proteins

influenza has …… on the viral surface

N spike, H spike

name the 2 protein spikes on the influenza viral surface

8 strand RNA

give the details of the influenza genome

changes

the influenza virus population regularly goes through ……

\-gradual mutational change

\-prior years immunity doesn’t protect against new versions

\-this is why we have yearly epidemics

pandemic

an extremely widespread and deadly epidemic

partial

most years we have ……. immunity to the new versions of the flu virus

\-our antibodies can recognize some of the new influenza virus but not all

antigenic shift

sometimes, the change to the flu antigens is so large that we lose all immunity

neuraminidase inhibitors

given to those with the flu who are at high risk of complications

neuraminidase inhibitors

blocks the maturation/spread of the virus

inactivated virus vaccine

kills flu virus particles, given by injection, can be given greater than 6 months of age

live attenuated virus vaccine

mutated virus, incapable of causing the flu, only for healthy people ages 2-49: can cause disease with weak immune systems

viral gastroenteritis/stomach flu

a viral infection of the stomach/intestines, can be caused by a large number of different viruses

fecal to oral

how is the stomach flu transmitted?

rotavirus

one large number of viruses that can cause viral gastroenteritis

double stranded RNA

rota virus genome is

naked

rotavirus is a …. virus making it resistant to soap and sensitive to alcohol

triple

rotavirus has a ….. capsid

hydration

rotavirus treatment

rotashield

based on a sheep virus related to human rotavirus, granted immunity, rare complication of intussusception

rotateq

based on a cow virus related to human rotavirus, causes a mild infection with no symptoms, grants immunity, no signs of complications

retrovirus

HIV/AIDs is a …..

envelope

HIV is an …….. virus

reverse transcriptase

enzyme that converts RNA to DNA

macrophages, T cells, dendritic cells

HIV infects

antibodies

when HIV attacks T cells, it stops the creation of

opportunistic infections

when T cell population decreases, the chance of …… …… increases

200

less than …… T cells is considered AIDS

A

which category of AIDS is least severe?

HAART

how to treat HIV

protease inhibitors

blocks enzymes needed for virion maturation

reverse transcriptase inhibitors

blocks viral reproduction

reverse transcriptase inhibitors, protease inhibitors

name the two major drugs HAART uses to treat HIV

CCR5

name the mutation that is HIV immune

CCR5

lacks protein used for HIV adsorption

prion

infectious proteins with no DNA or RNA, change the folding of proteins with the same sequence

transmissible spongiform encephalopathy

central nervous system cells die due to prions causing

prion diseases

spread by ingesting or having blood contact with infected nervous tissue

none

treatment for kuru/prion diseases

prions

hardy, pass through filters, and can resist autoclave temperatures