Module 6: Amino Acids and Proteins Obj. 1 Flashcards
Define Amino acids
organic molecules consisting of at least one amino group (basic) and one carboxyl group (acidic)
most significant optical isomer form of amino acids in humans
L- most significant in human physiology
essential amino acids
9/20 amino acids used to build proteins in cells that are essential
Valine Leucine Isoleucine Methionine Tryptophan Phenylalanine Threonine Lysine Histadine
non-essential amino acids
can be synthesized from others
glycine alanine cysteine asparagine glutamine serine tyrosine arginine aspirate glutamate proline
properties of ionization
amino acids ionize in water solutions into “zwitterions” (molecules possessing negative and positive charges)
Neutral amino acid in solution is a zwitteron that has equal # of pos and neg charges (net charge of zero)
properties of amphoterism
amino acids can act as either acids or bases (called ampholytes)
usually have net neg charge at alkaline pH and net pos charge in acid pH
formation of peptide bonds
amino acids joined together into peptides (and into polypeptides) by peptide bonds (dehydration)
A peptide has one less peptide bond than the # of amino acids in it
term for polypeptides with greater than 50 amino acids
polypeptide
