AP Bio Unit 1

Water

• Water consists of 2 hydrogen atoms covalently bonded to one oxygen atom Mickey Mouse

• Polar Molecule - molecule with uneven charge

Properties of Water

• Adhesion - water molecules stick to solid surfaces graduated cylinder
• Cohesion - water molecules stick to other other water molecules
• Water has a high surface tension
• Capillary action - when water molecules move upward through narrow tubes
• Water has a high specific heat
• Constant temp 98.6
• Water expands when it freezes
• pH - a scale used to determine if an aqueous solution is an acid or a base (H+) (OH-) In pure water same amount
• Acid - donate H+ to solution
• Base - Substance that donates OH- or accept H+ to a solution, sometimes called alkaline, bleach, ammonia
• Buffers - Substances that minimize concentrations of H+ and OH- in a solution. Donate H+ when pH goes up and accept H+ when pH goes down.

Organic Chemistry

• Study of carbon based molecules
• Carbon is very versatile
• Hydrocarbons - Molecules that contain only carbon and hydrogen
• The simplest hydrocarbon is methane
• Isomer - Molecules with the same molecular formulas but different structural formulas.
• 3 types of isomers are : structural, geometric, enantiomers
• Structural isomers - Differ in the covalent arrangement of their atoms
• Geometric isomers - Covalent partnerships of atoms are the same, but differ in their special arrangement
• Enantiomers - Also called stereoisomers. Molecules that are mirror images.