Proteins

• The mouth and stomach mechanically digest proteins
• Stomach acid denatures the quaternary and tertiary structures of proteins
• Pepsin is an enzyme in the stomach that hydrolyses peptide bonds
• The pancreas secretes trypsin, an enzyme that hydrolyses peptide bonds after the stomach
• Endopeptidases digest internal peptide bonds
• Exopeptidases hydrolyse peptide bonds at the end of a chain
• Pepsin and trypsin are endopeptidases
• Membrane bound dipeptidases can be reused
• Membrane bound dipeptidases hydrolyse dipeptides into single amino acids that can be absorbed into the blood stream
• Amino acids are absorbed in the small intestine
• Sodium and amino acids are co-transported