Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria Domain

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Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria Domain Archaea Common ancestor Domain Eukarya

Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria Domain Archaea Common ancestor Domain Eukarya

Bacteria live EVERYWHERE! n Bacteria live in all ecosystems ¨ on plants & animals

Bacteria live EVERYWHERE! n Bacteria live in all ecosystems ¨ on plants & animals ¨ in the soil ¨ in depths of the oceans ¨ in extreme cold ¨ in extreme hot ¨ in extreme salt ¨ on the living ¨ on the dead Microbes always find a way to make a living!

Bacterial diversity rods and spheres and spirals… Oh My!

Bacterial diversity rods and spheres and spirals… Oh My!

Compare prokaryotes to eukaryotes on the basis of…. Size n Genome n Reproductive strategies

Compare prokaryotes to eukaryotes on the basis of…. Size n Genome n Reproductive strategies n

eukaryote cell Prokaryote Structure n Unicellular ¨ bacilli, n cocci, spirilli Size ¨ 1/10

eukaryote cell Prokaryote Structure n Unicellular ¨ bacilli, n cocci, spirilli Size ¨ 1/10 n n prokaryote cell size of eukaryote cell 1 micron (1 um) Internal structure ¨ no internal compartments no membrane-bound organelles n only ribosomes n ¨ circular n chromosome, naked DNA not wrapped around proteins

Prokaryote vs. Eukaryote Chromosome Prokaryote Eukaryote double helix

Prokaryote vs. Eukaryote Chromosome Prokaryote Eukaryote double helix

mitochondria Variations in Cell Interior cyanobacterium (photosythetic) bacterium aerobic bacterium chloroplast inter n for

mitochondria Variations in Cell Interior cyanobacterium (photosythetic) bacterium aerobic bacterium chloroplast inter n for p al memb h r like otosynt anes a h (thyl chlorop esis l akoi ds) ast nes a r b em m l a n inter spiration drion n e for r mitocho a like e) a t s i (cr

Endosymbiosis n What evidence is there? Membranes DNA Reproduction

Endosymbiosis n What evidence is there? Membranes DNA Reproduction

Prokaryote Cell Wall Structure Gram-positive bacteria peptide side chains cell wall peptidoglycan plasma membrane

Prokaryote Cell Wall Structure Gram-positive bacteria peptide side chains cell wall peptidoglycan plasma membrane That’s important for your doctor to know! protein peptidoglycan = polysaccharides + amino acid chains lipopolysaccharides = lipids + polysaccharides Gram-negative bacteria outer membrane of lipopolysaccharide s cell wall outer membran e peptidoglyca n plasma membran

Prokaryotic metabolism n How do bacteria acquire their energy & nutrients? ¨ photoautotrophs n

Prokaryotic metabolism n How do bacteria acquire their energy & nutrients? ¨ photoautotrophs n photosynthetic bacteria ¨ chemoautotrophs n oxidize inorganic compounds ¨ nitrogen, sulfur, hydrogen… ¨ heterotrophs n live on plant & animal matter n decomposers & pathogens

What characteristics make bacteria so evolutionarily successful? Reproductive strategies n Mutation n

What characteristics make bacteria so evolutionarily successful? Reproductive strategies n Mutation n

Bacterial Reproduction Asexual…. binary fission n Fast! E. coli can divide every 20 minutes!

Bacterial Reproduction Asexual…. binary fission n Fast! E. coli can divide every 20 minutes! n Short generation time = quick evolution n No sex, no problem! n

Mutations n All 12 populations evolved common characteristics ¨ Increase in size ¨ Faster

Mutations n All 12 populations evolved common characteristics ¨ Increase in size ¨ Faster growth rates n Something unique around 31, 500 generations in one population – ability to metabolize citrate

Do the math Probability of mutation in a given E. coli gene 1 in

Do the math Probability of mutation in a given E. coli gene 1 in 10 million per division (1 x 10 -7) n Every day, 2 x 1010 new E. coli in your intestine n Each E. coli has around 4, 300 genes n So how many new mutations in one day? n 9 million!

Swapping genetic info Plasmids n Transformation n Transduction n Conjugation n

Swapping genetic info Plasmids n Transformation n Transduction n Conjugation n

Bacterial “Sex” F stands for……Fertility! Can be on plasmid or chromosome

Bacterial “Sex” F stands for……Fertility! Can be on plasmid or chromosome

Transduction n Phages transfer bacterial DNA

Transduction n Phages transfer bacterial DNA

Diverse metabolic strategies Obligate aerobe n Obligate anaerobe n ¨ Fermentation ¨ Anaerobic respiration

Diverse metabolic strategies Obligate aerobe n Obligate anaerobe n ¨ Fermentation ¨ Anaerobic respiration (NO 3 -, SO 42 - in place of O 2 as final electron acceptor) Facultative anaerobe n Nitrogen fixation…N 2 to NH 3 n ¨ why are these guys so important?

Archaeans Halophiles – “salt lovers” n Thermophiles – “heat lovers” n Methanogens – “methane

Archaeans Halophiles – “salt lovers” n Thermophiles – “heat lovers” n Methanogens – “methane creators” n ¨ Use CO 2 to oxidize H 2, producing CH 4

Bacteria as pathogens n Disease-causing microbes ¨ plant n diseases wilts, fruit rot, blights

Bacteria as pathogens n Disease-causing microbes ¨ plant n diseases wilts, fruit rot, blights ¨ animal diseases tooth decay, ulcers n anthrax, botulism n plague, leprosy, “flesh-eating” disease n STDs: gonorrhea, chlamydia n typhoid, cholera n TB, pneumonia n lyme disease n

Bacteria as beneficial (& necessary) n Life on Earth is dependent on bacteria ¨

Bacteria as beneficial (& necessary) n Life on Earth is dependent on bacteria ¨ decomposers n recycling of nutrients from dead to living ¨ nitrogen n only organisms that can fix N from atmosphere ¨ ¨ ¨ help n needed for synthesis of proteins & nucleic acids plant root nodules in digestion (E. coli) digest cellulose for herbivores ¨ n cellulase enzyme produce vitamins K & B 12 for humans ¨ produce n fixation foods & medicines from yogurt to insulin

Got any Questions? ?

Got any Questions? ?