Slide 1 Chemistry for MicrobiologyLecture 3 ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Slide 2 Biol 240 S06 2Learning Outcomes• Review – chemical reactions– Bonding– Oxidation and Reduction reactions– pH• Biological Molecules ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Slide 3 Biol 240 S06 3• Atoms want a complete outer electron shell• Losing an electron  positive cation• Gaining an electron  negative anion– Opposites attract – BUT bonds disrupted by waterIons and Ionic bondsFigure 2.2a11 e-10 e-17 e-18 e- ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Slide 4 Biol 240 S06 4Other Bonds• Iconic Bonds• Ironic Bonds ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Slide 5 Biol 240 S06 5• Two atoms share one or more pairs of electrons forming strong bonds– Molecules– Bonds NOT disrupted by waterCovalent BondsFigure 2.3a ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Slide 6 Biol 240 S06 6• Different ends ‘poles’have different charges• ~ O slightly –ve; H slightly +veWater is a Polar MoleculeFigure 2.4a ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Slide 7 Biol 240 S06 7• Ionic compounds dissociate, forming solutes– They dissolveWater as a SolventFigure 2.5