Intestinal Absorption

• Glucose and galactose by facilitated diffusion requiring the presence of high concentration of external Na ion

  sugars
• Fructose does not require Na and transported by a passive mechanism

  sugars
• transport of amino acids will be passive in nature

  amino acids
• Triglycerides are resynthesized utilizing the partial glycerides or acyloglycerols

  fatty acids
• resynthesis fats pass into the lacteals or lymphatic vessels to large thoracic duct and enters the blood

  fatty acids
• binds with an intrinsic factor secreted by the gastric mucosa

  Vitamin B12
• converted to folate before they are absorbed vitamin A binds with retinol bonding protein before it is absorbed

  Folic acid
• Na, K, Ca, Mg, transported by means of

  carrier molecules
• diffusion of ions more difficult than diffusion of molecules because passage depends not only on concentration gradient but also on electrical gradient

  inorganic ion transport