2/28/12 What is a halophile? Key Term: archaea

3/1/12 What compound makes up the cell wall of a bacterium? Key terms: same as yesterday

Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria Archaea Eukarya Common ancestor 2007-2008

Bacteria Structures

Bacteria Structures/Functions Flagella Tail-like structure for movement Pili Projection of cell wall for sticking to surfaces Cell wall Maintains shape of cell; protects the cell Cell membrane Regulates what leaves and enters the cell DNA Stores hereditary information Ribosomes Builds proetins

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

Genetic variation in bacteria Mutations bacteria can reproduce every 20 minutes binary fission error rate in copying DNA 1 in every 200 bacteria has a mutation Genetic recombination bacteria swap genes plasmids small supplemental circles of DNA

Genetic Recombination Type Source of New genes Entry method Transformation DNA in surroundings Endocytosis Transduction Virus w/bacterial DNA Viral mediated entry Conjugation Other bacteria Pili bridge http://www.phschool.com/science/biology_place/labbench/lab6/concepts1.html http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter13/animation_quiz_2.html http://www.hhmi.org/biointeractive/animations/conjugation/conj_frames.htm

Archaebacteria Extremophiles: Thermoacidophiles – love heat (up to 110’C) and acidic environments; require sulfur; anaerobic ex: Sulfolobus, Pyrodictium Halophiles –love environments with high salt concentrations like the Great Salt Lake and the Dead Sea; nearly all aerobic; all Gram-negative ex: Halococcus Methanogens – anaerobic methane producers; use carbon dioxide; live in soil, swamps, digestive tracts ex: Methanococcus

Bacterial diversity rods and spheres and spirals… Oh My!

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

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

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

Variations in Cell Interior cyanobacterium (photosythetic) bacterium aerobic bacterium internal membranes for photosynthesis like a chloroplast (thylakoids) internal membranes for respiration like a mitochondrion (cristae)

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

Do you recognize…?

Bacteria as beneficial (& necessary) Life on Earth is dependent on bacteria decomposers recycling of nutrients from dead to living nitrogen fixation only organisms that can fix N from atmosphere needed for synthesis of proteins & nucleic acids plant root nodules help in digestion (E. coli) digest cellulose for herbivores cellulase enzyme produce vitamins K & B12 for humans produce foods & medicines from yogurt to insulin

Pathogenic Bacteria Name of bacteria Can you predict the shape from name? Gram-Stain (+ = purple, = pink) Shape Notes