prokaryotes Flashcards
Photosynthesis
Oxygenic: produces O2
Anoxygenic: produces sulfur
Prokaryotic features
Unicellular Small No nuclei Double stranded DNA found in nucleoid No internal compartmentalization Simple flagella Reproduce via binary fission All gene transfer is horizontal
Classification of species
Photosynthetic? Motile? Unicellular or filamentous? Binary fission or spores? Human pathogen?
Horizontal gene transfer
Conjugation: cell to cell contact
Transduction: by bacteriophages
Transformation: from environment
Conjugation
Presence of f+ plasmid
Has pilus that reaches out to F-
F plasmid can integrate into chromosome and then is replicated with each division
Inaccurate transfer= F’ partial diploid
Transduction
Generalized: occurs via accidents in lytic cycle
Viruses package DNA and carry it
Specialized: accidents in the lysogenic cycle
Imprecise excision of prophage DNA
Lytic cycle
Phage attaches to cell
Shoots in viral DNA
destroys host
Packages up leftover DNA to crate 200 more phases
Lysogenic
Phage adopts some of cells DNA
Attaches to host cell
Transformation
Natural: DNA released when cell does and others pick it up
Artificial: done in the lab for gene transfer
Mutation
Arise due to environment
Spread rapidly
Make it difficult to fight something that’s constantly changing
Beneficial prokaryotes
Decomposers
Photosynthisizers
Nitrogen fixers
Bio factories
Prokaryote metabolism
Autotrophs
Heterotrophic
Chemolithotroph
Phototroph