AP Biology Unit 1 Test
water - --polar molecule
-polar colvalent bonds
-oxygen end is partial negative and the hydrogens have a partially positive end
-cohesive
polar covalent bonds - --opposite ends of the molecule have opposite charges
cohesion - --H bonding between H2O creates it (sticky)
-allows for the movement of water against gravity
-high surface tension
-water moves up a tree by transpiration (helped by ____)
adhesion - --H2O molecules form H bonds with other substances
~capillary action
~meniscus
~water climbs up fiber
solvent - --water is the universal one
-polar water molecules will surround the (+) and (-) ions causing the ions to separate
and dissolve
-dissolve solutes and create aqueous solutions
hydrophilic - --some molecules have an affinity for water
-polar and ionic molecules
-ex: cotton, cellulose, paper
hydrophobic - --some substances do not have an affinity for water
-nonpolar and non ionic substances
-ex: fat, glycerol, oils
floats - --less dense when it is solid, water ______
-forms crystal lattice structure
-important because oceans and lakes do not freeze solid
~insulates water below
~seasonal turnover of lakes
specific heat - --the amount of heat that must be absorbed or lost for 1g to change its
temperature by 1C
-water had high _____ due to H bonding
-resists change in temp
-moderates temp on earth
AP
, AP
evaporative cooling - --organisms use to regulate their temperature
-ex: sweating
-water evaporates through a surface, cooling occurs
acidic - -If [H+]>[-OH]
basic - -If [-OH]>[H+]
pH scale - --how acidic or basic a solution is
-pure water, only 1 molecule in every 554 million is dissociated
-most biological fluids have 6-8
-each unit represents a 10-fold difference in H+ and -OH concentrations
neutral - --If concentration of 2 ions is equal
carbon - --all life mostly based on this element
-important due to its electron configuration
~able to make 4 stable covalent bonds (tetra valence)
~very versatile
-tetravalence allows them to be strung together in chains
hydrocarbons - --combinations of C and H
-nonpolar
~not soluble in water
~hydrophobic
-stable
-very little attraction between molecules
-gas at room temp
isomers - --molecules with the same molecular formula but different structures
-different chemical properties
-different biological functions
structural isomers - --differ in covalent arrangement of atoms
geometric isomers - --same covalent relationships by different spatial arrangements
enantiomers - --isomers that are mirror images of each other
-structural differences create important functional significance
functional groups - --substitute other elements for hydrogen
-parts of organic molecules that are involved in chemical reactions
-give organic molecules distinctive properties
-affect reactivity
~make hydrocarbons hydrophilic
AP