Viruses: Living or Non Viruses: Living or Non Living?Living?
Phage = virusPhage = virus BacteriophagBacteriophag
e = virus with e = virus with bacteria hostbacteria host
Virus = Virus = genetic info genetic info with protein with protein shellshell
Viruses: Hershey – Chase Viruses: Hershey – Chase ExperimentExperiment
Viruses: Reproductive CycleViruses: Reproductive CycleLytic vs LysogenicLytic vs Lysogenic
Viruses: RetrovirusViruses: Retrovirus HIV: HIV: RetrovirusRetrovirus RNA instead of RNA instead of
DNADNA Enzyme Enzyme reverse reverse
transcriptasetranscriptase Once in host, Once in host,
converts RNA converts RNA into DNA into DNA (reverse (reverse transcription)transcription)
Viruses: RetrovirusViruses: Retrovirus Reverse TranscriptionReverse Transcription
Classification: DomainsClassification: Domains Major Division of Major Division of
Life: Prokaryotes Life: Prokaryotes vs. Eukaryotesvs. Eukaryotes
Domain: ArchaebacteriaDomain: Archaebacteria Archaea live in Archaea live in
EXTREME conditionsEXTREME conditions anaerobic swampsanaerobic swamps salt lakessalt lakes acidic hot springsacidic hot springs deep-sea deep-sea
hydrothermal ventshydrothermal vents animal digestive animal digestive
systems systems
Kingdom MONERA Kingdom MONERA (Bacteria)(Bacteria)
Prokaryotes - Prokaryotes - oldest life-formsoldest life-forms Remain most Remain most
numerous and numerous and widespread widespread organisms on organisms on Earth todayEarth today
Kingdom MONERAKingdom MONERA Prokaryotic: no Prokaryotic: no
nucleus, no nucleus, no organellesorganelles
Single-celled, Single-celled, Contains double-Contains double-stranded circular stranded circular chromosomal DNAchromosomal DNA
Cell wall: Cell wall: peptidoglycanpeptidoglycan
Kingdom MONERA: ShapesKingdom MONERA: Shapes Spheres (cocci): Spheres (cocci):
most commonmost common
Rods (bacilli)Rods (bacilli)
Curves or spirals Curves or spirals
Kingdom MONERAKingdom MONERA Cyanobacteria:Cyanobacteria:
AutotrophsAutotrophs Photoautotrophs and ChemoautotrophsPhotoautotrophs and Chemoautotrophs
Bacteria:Bacteria: heterotrophsheterotrophs
Kingdom MONERA: Kingdom MONERA: Genetic EngineeringGenetic Engineering
Bacteria can reproduce Bacteria can reproduce both asexually (both asexually (binary binary fissionfission) and sexually) and sexually
This discovery led to the This discovery led to the development of development of recombinant DNA recombinant DNA technologytechnology a set of techniques for combining a set of techniques for combining
genes from different sourcesgenes from different sources
Kingdom MONERA:Kingdom MONERA:Gene ExchangingGene Exchanging
Can occur in 3 waysCan occur in 3 ways TransformationTransformation: :
taking up of DNA taking up of DNA from the fluid from the fluid surrounding the cellsurrounding the cell
DNA enterscell
Fragment ofDNA from anotherbacterial cell
Bacterial chromosome(DNA)
Kingdom MONERA:Kingdom MONERA:Gene ExchangingGene Exchanging
Transduction:Transduction: transfer of transfer of bacterial genes by bacterial genes by phage (virus)phage (virus)
ConjugationConjugation: union : union of cells and the DNA of cells and the DNA transfer between transfer between themthem
Phage
Fragment ofDNA from anotherbacterial cell(former phagehost)
Kingdom MONERA: PlasmidsKingdom MONERA: Plasmids PlasmidPlasmid: a : a
small circular small circular DNA DNA molecule molecule separateseparate from the from the bacterial bacterial chromosomechromosome
Kingdom MONERA:Kingdom MONERA:Genetic EngineeringGenetic Engineering Restriction Restriction
enzymesenzymes cut DNA cut DNA at specific pointsat specific points
DNA ligaseDNA ligase “pastes” the DNA “pastes” the DNA fragments fragments togethertogether
The result is The result is recombinant DNArecombinant DNA
Kingdom MONERA:Kingdom MONERA:Recombinant DNARecombinant DNA