Chemistry of Life HBio Ch 2

Review of the atom Which part is most reactive (able to do WORK?)

Chemical bonding All LIFE is chemical reactions –metabolism Based on electron stability –Ionic bonds Oxidation/reduction reactions –Covalent bonds Chemical bonds store energy more bonds = more potential energy stored –Ex: potential energy in food is converted to kinetic energy in our bodies –Digestion (which uses water) breaks bonds – releases energy

Carbon loves to bond covalently That’s why carbon is the BASIS of all life

A polar molecule Properties of water –Polar –85% of our body –Evaporative cooling –High specific heat Holds heat for a long time That’s why water maintains the big “H”

Water bonds easily with itself Polarity Hydrogen bonds –Cohesion –Adhesion –Capillary action

Hydration Shells

dissolve = hydrolysis put together = dehydration synthesis

Water ‘falls apart’ (dissociates) to form H+ ions and OH- ions pH scale is a measure of H+ ions in solution Lots of H+ (acid) Lots of OH- (base)