Summary of Digestion and Absorption of Different Macronutrients by Region Protein Carbohydrates Lipids ORAL CAVITY - Salivary Amylase Lingual Lipase ESOPHAGUS - - - STOMACH Protein Stimulus: anticipation Pepsin (secreted by of a meal or arrival of chief cells as bolus pepsinogen, converted to active Hormone: Gastrin pepsin by HCl) Polypeptides SMALL INTESTINE Trypsin Amylase Bile Salts and Chymotrypsin (pancreatic) Lipase Stimulus: arrival of Carboxypeptidase (pancreatic) acidic chyme (all are secreted as Hormone: CCK inactive proenzymes trypsin is activated – intially by enterokinase, trypsin in turn activates others) Mono, Di & Monoglycerides and Amino Acids & Short Trisaccharides Fatty Acids Peptides (Simple Sugars) INTESTINAL MUCOSA Peptidases Lactase Maltase (brush border enzymes) Sucrase Monoglycerides and Amino Acids Monosaccharides Fatty Acids Facilitated Diffusion and Facilitated Diffusion Diffusion Cotransport and Cotransport Monoglycerides and Fatty Acids Triglycerides Amino Acids Monosaccharides Chylomicrons CIRCULATION Facilitated Diffusion and Facilitated Diffusion Exocytosis Cotransport and Cotransport Amino Acids Monosaccharides Chylomicrons
Summary of Digestion and Absorption of Different Macronutrients by Region Protein Carbohydrates Lipids ORAL CAVITY - Salivary Amylase Lingual Lipase ESOPHAGUS - - - STOMACH Stimulus: anticipation of a meal or arrival of bolus Hormone: Gastrin Protein Pepsin (secreted by chief cells as pepsinogen, converted to active pepsin by HCl) Polypeptides SMALL INTESTINE Stimulus: arrival of acidic chyme Hormone: CCK Trypsin Chymotrypsin Carboxypeptidase (all are secreted as inactive proenzymes – trypsin is activated intially by enterokinase, trypsin in turn activates others) Amino Acids & Short Peptides Amylase (pancreatic) Mono, Di & Trisaccharides (Simple Sugars) Bile Salts and Lipase (pancreatic) Monoglycerides and Fatty Acids INTESTINAL MUCOSA (brush border enzymes) Peptidases Amino Acids Facilitated Diffusion and Cotransport Amino Acids Lactase Maltase Sucrase Monosaccharides Facilitated Diffusion and Cotransport Monosaccharides Monoglycerides and Fatty Acids Diffusion Monoglycerides and Fatty Acids Triglycerides Chylomicrons CIRCULATION Facilitated Diffusion and Cotransport Amino Acids Facilitated Diffusion and Cotransport Monosaccharides Exocytosis Chylomicrons
48_lol_digestion.docx