Lecture 2/7

• there are 20 amino acids, humans are able to synthesize 11 of them, while the other 9 must be supplied
• aminoacidopathies are rare inherited disorders of amino acid metabolism
• phenylketonuria is a condition where the patient cannot metabolize phenylalanine
• alkaptonuria is a condition where the patient cannot metabolize tyrosine
• homocysteinuria is a condition where the patient cannot metabolize methionine
• to test for aminoacidopathies, we must use a plain red tube, spin and separate the serum, and freeze immediately
• hydrophobic amino acids are polar and hydrophobic

  R group will be symmetrical
• hydrophilic amino acids are polar and hydrophilic

  • tend to have uncharged polar R group
  • can have alcohol
• amino acids that are acidic will have acidic R groups
• amino acids that are basic tend to have amine groups that are positively charged
• 1 Dalton is the mass of a proton
• proteins are found in all body fluids, almost all secretions
• proteins are measured in Daltons
• proteins are macromolecules that comprise 50-70%f the cell dry weight
• proteins can be 6000D to millions of Daltons
• polypeptides are small chains of amino acids
• proteins are generally large chains of amino acids
• the charge of proteins is affected by the pH of the surroundings
• dipeptide is two aa
• tripeptide is three aa
• tetrapeptide is 4 aa
• beyond four aa joined together is a polypeptide
• most serum proteins we test for are helices
• in an acidic solution, aa may become positive or protein will denature and change shape
• protein shape will determine whether protein is functional or not