ap bio module 2: water

polar

molecule with different charges on each end/pole

hydrogen bond

partially positive hydrogen atom is attracted to a strongly electronegative atom (ex. oxygen)

cohesion

when water sticks to itself (high % of water molecules H bond to other water molecules)

adhesion

water sticks to other things (high % of water molecules H bond to a different molecule)

surface tension

measure of how hard it is to break the surface of a liquid; water does not pull apart easily & is a form of cohesion

specific heat

amount of heat that must be absorbed or lost for 1 gram of substance to change its temp by 1 degree Celcius (water has a high specific heat)

solvent

substance that does the dissolving (water is solvent of life)

solute

what is being dissolved

acid

chemical substance with more H+ ions than OH- ions, below 7 on pH scale

base

chemical substance with more OH- ions than H+ ions, above 7 on pH scale

what is the pH of pure water?

7

pH scale

ranges from 0 to 14, below 7 indicates more H+ ions and more acidic, above 7 indicates more OH- ions and more basic

dehydration synthesis reaction

chemical process where monomers join together to form a polymer while releasing one molecule of water (ex. ADP + inorganic phosphate + energy → ATP + H2O)

hydrolysis reaction

chemical process where water breaks down chemical bonds in a compound (ex. ATP + H2O → ADP + inorganic phosphate + energy)