Figure 25.1 Gastrointestinal organs and their functions. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.2 Exocrine secretion of digestive enzymes. Redrawn with permission from Jamieson, J. D. Membrane and secretion. In G. Weissmann and R. Claiborne (Eds.), Cell Membranes: Biochemistry, Cell Biology, and Pathology. New York: HP Publishing Co., 1975. Figure by B. Tagawa. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.3 Model of porcine pepsinogen NH2-terminus to be cleared in central groove and aspartic acid residues at active site (red). Model 3PSG from Protein Data Bank and illustrated with Protein Explorer. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.4 Cellular regulation of exocrine secretion in pancreas. Adapted from Gardner, J. D. Annu. Rev. Physiol. 41:63, 1979. Copyright (1979) by Annual Reviews, Inc. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.5 Acetylcholine. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.6 (a) L(+)-Muscarine. (b) atropine. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.7 Histamine. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.8 5-OH-Tryptamine (serotonin). Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.9 Pathways for transport across epithelia. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.10 Na+ concentrations and electrical potentials in enterocytes. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.11 Model for electrogenic NaCl absorption in lower large intestine. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.12 Amiloride. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.13 Model for electrically neutral NaCl absorption in the small intestine. Na+ absorption proceeds via sodium/proton exchanger 3(NHE3) and Na+, K+-exchanging ATPase. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.15 Ionic composition of gastrointestinal secretions. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.15 Model for epithelial NaCl secretion. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.16 Furosemide. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.17 Model for NaHCO3 secretion by pancreatic duct cells. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.18 Model for epithelial glucose absorption. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.19 Transepithelial glucose transport as translocation reactions across plasma membranes and the tight junction. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.20 Omeprazole, an inhibitor of K+/H+-exchanging ATPase. Redrawn from Sachs, G. The gastric K/H-ATPase. In Johnson, L. R. (Ed.), Physiology of the Gastrointestinal Tract. New York: Raven, 1994, 1133. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.21 Model for secretion of hydrochloric acid. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.22 Digestion and absorption of proteins. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.23 Secretion and activation of pancreatic enzymes. Abbreviation: CCK, cholecystokinin. Reproduced with permission from Freeman, H. J., and Kim, Y. S. Annu. Rev. Med. 29:102, 1978. Copyright (1978) Annual Reviews, Inc. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.24 Model for heteromeric amino acid transporter. Redrawn from Chillaron, J., Roca, R., Valencia, A., Zorzano, A., and Palacin, M. Heteromeric amino acid transporters: biochemistry, genetics, and physiology. Am. J. Physiol. Renal Physiol. 281:F995, 2001. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.25 Digestion and absorption of carbohydrates. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.26 Digestion of amylopectin by salivary and pancreatic α-amylase. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.27 Digestion and absorption of lipids. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.28 Changes in physical state during triacylglycerol digestion. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.29 Mechanism of action of lipase. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.30 Mechanism of action of phopholipase A2. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.31 Cholic acid, a bile acid. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.32 Solubility properties of bile acids in aqueous solutions. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.33 Diagrammatic representation of an Na+ cholate micelle. Adapted from Small, D.M. Biochim. Biophys. Acta 176:178, 1969. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.34 Proposed structure of mixed bile acid-phosphatidyl choline micelles. Adapted with permission from Marrink, S.J., and Mark, A. E. Biochem. 41:375, 2002. Copyright (2002) American Chemical Society. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.35 Enteroheptic circulation of bile acids. Redrawn from Clark, M. L., and Harries, J. T. In McColl. I., and Sladen, G.E. (Eds.), Intestinal Absorption in Man. New York: Academic Press, 1975, 195. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.

Figure 25.36 Transporters for taurocholate (TC) and phosphatidyl choline (PC) during enterohepatic circulation. Textbook of Biochemistry with Clinical Correlations, 7e edited by Thomas M. Devlin © 2011 John Wiley & Sons, Inc.