Lecture #20: Macromolecules Flashcards
Energy
The ability to do work
Potential energy
energy that matter has because of its position
- electrons moved to outer levels have greater potential energy
Energy levels
1st level - 2 e-
2nd level - 8 e-
Oxygen
8 e-
2 e- (first level)
6 e- (second level)
“wants 2 e-“
Hydrogen
1 e- (1st level)
Non-polar Covalent bonds
Equal sharing of e- within molecule
O2, most lipids (fats)
- nonpolar —> hydrophobic
Hydrogen bonds
Weaker than covalent (works at a distance)
1. between polar molecules
2. between sections of large molecules
Ionic bonds
NaCl
Water
Polar
cohesive, adhesive, good solvent, high heat capacity (storage)
Cohesive
sticks to itself (bc of hydrogen bonds)
Adhesive
Sticks to other polar molecules
Good solvent
for polar molecules, molecules w/ ionic bonds
High heat capacity
heats up and cools down slowly
Becomes denser as it cools down to 4C, but expands as it cools down
solid form is less dense than liquid form (ice floats on top)
Disassociate into ions (H2O –> H+ + OH-)
Ph
-log [H+ concentration]
pOH
-log [OH- concentration]
pH < 7
acidic (excess of H+ ion)
