Download Viruses

Viruses: Living or Non Living?
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Phage = virus
Bacteriophage
= virus with
bacteria host
Virus =
genetic info
with protein
shell
Viruses: Hershey – Chase
Experiment
Viruses: Reproductive Cycle
Lytic vs Lysogenic
Viruses: Retrovirus
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HIV: Retrovirus
RNA instead of
DNA
Enzyme reverse
transcriptase
Once in host,
converts RNA
into DNA
(reverse
transcription)
Viruses: Retrovirus
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Reverse Transcription
Classification: Domains
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Major Division of
Life: Prokaryotes
vs. Eukaryotes
Domain: Archaebacteria
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Archaea live in
EXTREME conditions
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anaerobic swamps
salt lakes
acidic hot springs
deep-sea
hydrothermal vents
animal digestive
systems
Kingdom MONERA (Bacteria)
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Prokaryotes - oldest
life-forms
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Remain most
numerous and
widespread
organisms on Earth
today
Kingdom MONERA
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Prokaryotic: no
nucleus, no organelles
Single-celled, Contains
double-stranded
circular chromosomal
DNA
Cell wall:
peptidoglycan
Kingdom MONERA: Shapes
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Spheres (cocci):
most common
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Rods (bacilli)
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Curves or spirals
Kingdom MONERA
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Cyanobacteria:
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Autotrophs
Photoautotrophs and Chemoautotrophs
Bacteria:
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heterotrophs
Kingdom MONERA:
Genetic Engineering
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Bacteria can reproduce both
asexually (binary fission)
and sexually
This discovery led to the
development of recombinant
DNA technology
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a set of techniques for combining
genes from different sources
Kingdom MONERA:
Gene Exchanging
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Can occur in 3 ways
Transformation: taking
up of DNA from the fluid
surrounding the cell
DNA enters
cell
Fragment of
DNA from
another
bacterial cell
Bacterial chromosome
(DNA)
Kingdom MONERA:
Gene Exchanging
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Transduction:
transfer of bacterial
genes by phage
(virus)
Phage
Fragment of
DNA from
another
bacterial cell
(former phage
host)
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Conjugation: union of
cells and the DNA
transfer between them
Kingdom MONERA: Plasmids
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Plasmid: a
small circular
DNA molecule
separate from
the bacterial
chromosome
Kingdom MONERA:
Genetic Engineering
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Restriction enzymes
cut DNA at specific
points
DNA ligase “pastes”
the DNA fragments
together
The result is
recombinant DNA
Kingdom MONERA:
Recombinant DNA