Chapter 2: Biochemistry Flashcards
ground state
if all the electrons are in the lowest available energy levels
excited state
when an atom absorbs energy, electrons move to higher energy level
isotope
atoms of an element that vary only in number of neutrons , in nature, element occurs as mixture of isotopes
bonding
formed when two nuclei attract the same electrons, energy released bc atoms acquire a more stable configuration by completing their outer shells
energy
must be supplied to break bond
ionic bonds
from transfer of electrons
anion
[a n]egative [ion]
cation
a positive ion (has t == +)
covalent bonds
atoms share electrons, resulting structure is molecule
single cov. bond
two atoms share 1 pair of e-
double cov. bond
two atoms share 2 pair of e-
triple cov. bond
same as last 2
non polar cov. bond
shared equally, found in diatomic molecules
polar cov. bond
shared unequally, found in any two different atoms
diatomic molecules
Have No Fear of Ice Cold Beer (hydrogen, nitrogen, flourine, oxygen, iodine, chlorine, bromine)
hydrophilic def.
water loving
hydrophilic substances
polar, have charge, ionic
water name
universal solvent
hydrophobic def.
water hating
hydrophobic substances
non polar, will instead dissolve in lipids
miscible
able to dissolve in one another
pH
measure of acidity and alkalinity of a solution
acid
pH is less than 7
alkaline substance, or basic
pH is greater than 7
