Bio - Chapter 26 -Viruses

Front 1

capsid

Back 1

protein sheath around the nucleic acid core of a virus. composed of one to a few different protein molecules repeated many times.

Front 2

envelope

Back 2

formed around capsid in animal proteins - made from proteins, lipids, and glycoproteins. contains proteins from host and viral genes.

Front 3

host range

Back 3

suitable cells for a particular virus

Front 4

helical

Back 4

shape of virus that has rodlike or threadlike appearance

Front 5

isometric

Back 5

shape of virus that is spherical shape

Front 6

icosahedron

Back 6

structure with 20 equilateral triangular facets found in isometric viruses

Front 7

bacteriophages

Back 7

viruses that infect bacteria
-some named as members of a "t" series

Front 8

lytic cycle

Back 8

when a virus kills the infected host cell in which is is replicating
- whiskers grab on to cell wall
-tail contracts and tail tube passes through base plate, piercing cell wall
-contents injected into host cytoplasm

Front 9

virulent viruses

Back 9

viruses that multiply within infected cells and eventually lyse (rupture) them.
ex: T series bacteriophages

Front 10

prophage

Back 10

nucleic acid of bacteriophages that is integrated into genome of infected host cell

Front 11

lysogeny

Back 11

integration of a cirus into a cellular genome

Front 12

lysogenic cycle

Back 12

reproductive cycle involving a period of genome integration

Front 13

lysogenic viruses (or temperate viruses)

Back 13

viruses that become stably integrated within the genome of their host cells

Front 14

transformation

Back 14

genetic alteration of a cell's genome by the introduction of foreign DNA

Front 15

phage conversion

Back 15

alteration caused when foreign DNA contributed by bacterial virus

Front 16

retrovirus

Back 16

an RNA virus that transribes its genes into DNA
ex: HIV

Front 17

reverse transcriptase

Back 17

enzyme that synthesizes a double strand of DNA complementary to the virus RNA, often making mistakes and so introducing new mutations

Front 18

future of HIV treatment

Back 18

combination drug therapy
vaccine therapy
blocking replication
disabling receptors

Front 19

chemokines

Back 19

chemicals that inhibit HIB infection by binding to and blocking the CCR5 and CXCR4 coreceptors.

Front 20

emerging viruses

Back 20

viruses that originate in one organism and then pass to another and cause disease

Front 21

hantavirus

Back 21

single stranded RNA virus associated with rodents (specifically deermice in an outbreak in southwestern US, 1993)

Front 22

Ebola virus

Back 22

causes severe hemorrhagic fever
-natural host is still unknown

Front 23

severe acute respirator syndrome (SARS)

Back 23

comes from civets (weasel like mammal)from a species of coronavirus

Front 24

TSEs (transmissible spongiform encephalopathies)

Back 24

causes mad cow disease
comes from prions

Front 25

prion

Back 25

proteinaceous infectious particle
no DNA or RNA
discovered by Alper and Griffith

Front 26

viroids

Back 26

tiny, naked molecules of RNA that are important infectious disease agents in plants
-resemble the sequence of introns within the rRNA genes cause destruction of chromosomal integrity.