Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
80 Cards in this Set
- Front
- Back
Viruses are
|
obligate intracellular parasites
|
|
Viruses require:
|
living hose cell in order to replicate (must invade & take over host cells functions & resources
|
|
how many viruses have a complete mechanism for nucliec acid?
|
none
|
|
viruses usually have no mchanism for __________
|
expression of their genes
|
|
What facilitates transfer of viral nucliec acid to the host?
|
a protien coat & additional specialized structures &/or enzymes
|
|
a complete virus particle is called _________
|
a virion (the product released)
|
|
2 Major Structures of viruses
|
1. naked nucleocapsid
2. enveloped virus |
|
if a virus is naked it is just....
|
protien & nucliec acid
|
|
Capsid is a...
|
protective outer chell that surrounds viral nucliec acid
|
|
capsids are composed of
|
capsomer subunits
|
|
3 types of Capsid structure
|
1.Helical
2. Icosahedral 3. Complex |
|
Helical Capsids have...
|
rod-shaped capsomers that form hollow discs that resemble a braclet
|
|
a naked helical virus is..
|
rigid & tightly wound into a cylinder shaped package
|
|
In a enveloped helical virus the nuclio capsid is...
|
more flexible
|
|
Icosahedron Capsid is...
|
3 deminsional, 20 sided w/ 12 evenly spaced corners
|
|
variation in capsomer number
|
polio virus 32 capsomer
adenovirus 240 capsomer |
|
1 cosahdral virus can be
|
naked OR envelope
|
|
during the release of animal virus (envelope)...
|
a part of the host membrane is taken (lipid & host proteins)
|
|
envelope enables __________ of the virus
|
pleomorphic shape
|
|
Function of the capsid/envelope
|
1.protect nucliec acid from hosts nucliec acid & protein digesting enzymes
2.assist in binding & penetrating host cell 3.avoids the stimulation of the hosts immune system |
|
complex virus structures are...
|
more intricate than helical & icosahedral viruses
|
|
complex virues have...
|
several layers of lipoprotein & course surface fibrils
|
|
bacteriophage has...
|
polyhedral head, helical tail, fibers for attachment
|
|
tail fibers & pins-
|
attach virus to specific sites on the cell surface of the bacterium
|
|
viruses contain either
|
DNA OR RNA
|
|
viruses possess only the genes to-
|
invade & regulate the metabolic activity of the host cell
|
|
there are no viral metabolic genes;
|
as the virus uses the hosts metabolic resouces
|
|
VR-
adsorption |
virus bings to host cell
|
|
VR-
penetration |
virus enters host cell
|
|
VR-
uncoating |
viral nucliec acid is exposed for replication machinery
|
|
VR-
synthesis |
viral nucliec acid is replicated, transcribed, and translated
|
|
VR-
assembly |
viral virion components are assembled
|
|
VR-
release |
mature virions are released to infect the next cell
|
|
penetration of animal viruses occur by ______ or ______ between the viral envelope & the host cell membrane
|
endocytosis
fusion |
|
uncoating & synthesis of viruses rely on the....
|
hosts metabolic systems
|
|
a mature virus can obtain a _____ by ________
|
envelope,
by budding off the host cell (envelope virus way) |
|
instead of budding a virus can _________ to _________
|
lyse,
release the viral progeny aka "popping the cell" (naked viruses) |
|
scaffolding proteins-
|
help assembly of the capsid & then removed; other viral protiens are involved in final maturation
|
|
release involves pahge ________ & ____________ to form holes in it
|
endolysin & holin
|
|
virulent phage only have a....
|
lytic life cycle
|
|
after viral multiplication inside the host cell, viral enzymes will......
|
weaken the host cell membrane, rupture the cell (lyses), and release numerous virions
|
|
lysogeny is when....
|
the bacteriophage can insert its DNA into the bacterial host genome
|
|
prophage =
|
inovated its genome into it's host genome
|
|
WHO estimates _______ people are infected w/ HIV
|
45 million
|
|
AIDS is not a disease, but a...
|
syndrome
|
|
AIDS syndrome is....
|
any of certain oppurtunistic or rare infections that occur in the presence of antibodies agaist the human immundoefiecny virus (HIV)
|
|
HIV likely arouse from...
|
mutation of the simian immunodeficency virus (SIV) found in African monkeys
|
|
HIV only replicates....
|
in humans & destroys the human immune system
|
|
2 major types of HIV
|
HIV1 & HIV2
|
|
HIV1 is...
|
prevalent in US & Europe
|
|
HIV2
|
prevalen in west Africa
|
|
AIDS first recognized in...
|
young homosexual males in the US
|
|
HIV is found in...
|
sufficient concentrations to cause infections in blood, semen, saliva, vaginal secretions, & breast milk
|
|
most infectious secretions of HIV:
|
blood & semen
|
|
immunology
|
study of the development of resistance in infectious agents by the body
|
|
remember 3 immunology things:
|
surveillance of the body, recognition of forgien material, & destruction of forgien material of agents
|
|
host defenses can be divided into two distinct branches:
|
1.innate immunity & 2. adaptive response
|
|
innate immunity-
|
NONspecific host defenses to infection
|
|
adaptive response-
|
host response to specific microbial infection (also to anything else that happens to enter the body)
|
|
1stLofD
intact skin- |
low mositure, low pH; oily (sebum) residues inhibit microbes; desquamation (shed dead skin layers
|
|
1stLofD
conjuctiva (EYES)- |
(lacrimal apparatus) tear dilution & lysozyme
|
|
1stLofD
outer ear- |
antibacterial activity of waxes
|
|
1stLofD
mucus membranes-(gastroentestinal, genitournary, resptitory) |
gastro- saliva,(swalling, lysozymes, antibodies), stomach acids, intestinal mucis w/ antibacterial substances & antibodies
genitour- low pH levevl & high salt or urine flush urinary tract, acid vagina, lysozymes in seminal fluids respitory- nasal hairs, nasal passages, cilited spithelium, clearing/coughing, alveoli macrophage |
|
normal flora (bacterial antagonsim)-
|
harmless bacteria compete w/ pathogens & may produce bacteriocins
|
|
the trachea contain ______ that ______ & ________
|
cilia
entrap & propel particles out of the respitory tract |
|
2ndLofD
white bloods cells = |
leukocytes
|
|
**** phagocytosis-
|
endocytosis of a microbe or "agent" & it's subsequent destruction. It is enhanced in neutrophilis & macrophge by OPSONIZATRON
|
|
8888 opsonizatron
|
phagocyte adhesion to antibodies &/or compliment protein 3cb bound to microbes
|
|
WBC recognize....
|
self markers on the host cell
& nonself markers on the invading microbe |
|
WBC do not attack or respond to....
|
hosts cell
|
|
WBC don't destroy....
|
self cells while noself cells are recognized & destroyed
|
|
every cell comes from...
|
bone marrow
|
|
produce ________ blood cells per second
|
8 million
|
|
macrophage-
|
highly produced phageocytic; high surface area of pseudopods, maybe "wandering in blood or "fixed" in assocation w/ mucosal membranes in healthy tissue
|
|
dendritic cells-
|
molecular pattern associated receptors for detecting microorganism, present antigens to T-cells. Located throughout lymph system, skin, and other tissues
|
|
lymphocytes
|
involved in specific resistance
|
|
B CELLS-
|
lymph sysyem associated w/ specific clones recognize ANTIGEN & stimulate multiplication, some mature to antibody releasing plasma cells, others become a long living dormant population of "memory cells"
|
|
T CELLS-
|
lymph system associated, involved in chemical communication & stimulation of B cell antibody production & may become cytotoxic to kill infected cells
|
|
natural killer cells-
|
granular kill viral infected & tumor cells
|
|
systemic surveilance
|
1. lymphatic system
2. circulatory system (heart, veins & artiries) 3. tissue specific |