1. Enzymes
    • Help “catalyze” chemical reactions
  2. Structural Proteins
    • Give support, strength, flexibility
    • Examples: collagen, elastin, keratin
  3. Storage Proteins
    • Storage of amino acids, for building proteins later or energy
    • Examples: egg albumin (ovalbumin), Casein (in milk)
  4. Transport Proteins
    • Examples: Hemoglobin (O2), H+ pump
  5. Signaling Proteins
    • Hormonal Proteins and receptor proteins
    • Example: Insulin and Insulin receptor
  6. Motor Proteins
    • Actin and myosin perform muscle contraction
  7. Immune Defense Proteins
    • Antibodies help fight infection