Biochemistry Terms

Isotopes

atoms with same atomic number but different atomic mass

radioisotopes

an isotope with an unstable nucleus. emits subatomic particles

valence electrons

outer shell electrons, can be shared with another atom

electronegativity

tendency of an atom to hold on to electrons

ionic bond

bond formed by electrical attraction between a + and - ion

covalent bond

bond formed when atoms share electrons

polarity

unequal sharing of electrons causing partial charges

molecular polarity

the uneven distribution of electrons, charge is not symmetrical

intramolecular forces

forces between atoms in a molecule

intermolecular forces

forces between molecules

london forces

random movement of electrons causing temporary dipole attraction between molecules

hydrogen bond

attractive force between partial positive hydrogen atom and a partially negative atom in another molecule

acid

releases H+ ions in aq solution

base

releases OH- ions in aq solution

strong/weak acids

determined by the percentage of H+ ions that dissociate for the molecule

concentrated/dilute acid

determined by the actual mol/L of acid in solution

conjugate acid base pair

acid donates a H+ proton to make itself a conj base and make the base a conj acid

buffer

a weak acid and conj base that compensates for pH changes by accepting or donating H+ in solution

structural formula

molecular diagram showing bonds between atoms

isomer

molecule with the same chemical formula as another molecule but a different structural formula

macromolecule

large molecule typically made of repeating subunits

polymer

large number of molecular subunits linked together. all polymers are macromolecules but not vice versa

monomer

small molecule that combines with similar small molecules to form a polymer

functional groups

small configurations of atoms frequently found in molecules

carboxyl

COOH, can release H+ to become COO-, acid

amino group

NH2, can attract H+ to become NH3+, base

phosphate group

H3PO4, can lose H+ to become PO4 3-

carbonyl

C=O

aldehyde

An organic molecule with a carbonyl group and at least 1 H+ attached to 2 carbon atoms

ketone

carbonyl group bonded to 2 carbon atoms

sulfhydryl (thiol)

-SH

hydroxyl

-OH

metabolism

The chemical processes that occur within an organism in order to maintain life

anabolism

Chemical reactions that produce larger molecules from smaller ones

catabolism

Chemical reactions that produce smaller molecules from larger ones

dehydration synthesis

two monomers combine together and release a H2O

larger molecule and a water molecule is also formed in the process

hydrolysis

molecule of water is used to split two monomers apart