Lecture 17 Flashcards
(26 cards)
AIDS
symptoms and signs present during late stage HIV
bacteriophage / phage
A virus that
infects bacteria; also called a phage.
capsid
The protein shell that encloses a viral
genome. It may be rod-shaped, polyhedral,
or more complex in shape.
conjugation
In prokaryotes,
the direct transfer of DNA between
two cells that are temporarily joined.
When the two cells are members of different
species, conjugation results in horizontal gene transfre
F factor
In bacteria, the DNA segment that
confers the ability to form pili for conjugation
and associated functions required
for the transfer of DNA from donor to
recipient. The F factor may exist as a plasmid
or be integrated into the bacterial
chromosome.
generalized transduction
In generalized transduction, a small piece of the host cell?s degraded DNA is
packaged within a capsid, rather than the phage genome
HIV
human immunodeficiency virus)
The infectious agent that causes AIDS.
HIV is a retrovirus.
lysogenic cycle
A type of
phage replicative cycle in which the viral
genome becomes incorporated into the
bacterial host chromosome as a prophage, is
replicated along with the chromosome, and
does not kill the host.
lytic cycle
A type of phage replicative cycle resulting in the release of new phages by lysis (and death) of the host cell.
nucleoid
Nucleus Like
operon
A unit of genetic function
found in bacteria and phages, consisting of
a promoter, an operator, and a coordinately
regulated cluster of genes whose products
function in a common pathway.
plasmid
A small, circular, doublestranded DNA molecule that carries accessory genes separate from those of a bacterial chromosome; in DNA cloning, can be used as a vector carrying up to about 10,000 base pairs (10 kb) of DNA.
prion
Prions are infectious proteins that spread a diseas
prophage
A phage genome that has
been inserted into a specific site on a bacterial
chromosome.
provirus
A viral genome that is permanently
inserted into a host genome.
R plasmid
A bacterial plasmid carrying genes
that confer resistance to certain antibiotics.
retrovirus
an important class of cancer-causing viruses
reverse transcriptase
An
enzyme encoded by certain viruses (retroviruses)
that uses RNA as a template for DNA
synthesis.
specialized transduction
Specialized transduction occurs via a temperate phage, when the viral genome that is excised from the chromosome it sometimes takes with it a small region of adjacent bacterial DNA on the viral genome
temperate phages
Phages capable of using both modes
of replicating within a bacterium are called temperate phages
transduction
A process in which phages
(viruses) carry bacterial DNA from one bacterial cell to another. When these two
cells are members of different species, transduction
results in horizontal gene transfer.
(2) In cellular communication, the conversion
of a signal from outside the cell to a
form that can bring about a specific cellular
response; also called signal transduction.
transformation
The conversion of a
normal animal cell to a cancerous cell.
transposon
transposable element that
moves within a genome by means of a DNA
intermediate.
vaccine
A harmless variant or derivative
of a pathogen that stimulates a host?s immune
system to mount defenses against the
pathogen.
