GLUCONEOGENESISStep 1PyruvatePyruvateCO2+ATEcarboxylaseADP+PBiotinOxaloacetateGTPCOOCOGDPPEP十2PG4COOCOO3PCCO+--C=OCH2BPG1CH3COOADPG3PDAPPyruvateOxaloacetateFBPPyruvate-8carboxyiaseG6PBiotin1Glucose
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Step 1
ABIOCHEMISTRYANDMOLECULARBIOLOGYStep 1:+ ADP0O+PHCO,P-→+ATPCH,C-COOOOCCH,C-COOOxaloacetatePyruvateBicarbonateFIGURE 23.2 ● The pyriwate carboxylase reactionDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Step 1:
PEPCytosolGDP+ CO2PhosphoenolpyruvateGTPcarboxykinaseMalicOxaloacetic acidAspartateacidMalic acidAspartateNAD+a-ketoglutarateNADH + H+OxaloaceticacidGlutamic acidOnlyinADP+PimitochondriaPyruvateATP+ CO2carboxylasepyruvateMitochondriapyruvate
pyruvate pyruvate Oxaloacetic acid Pyruvate carboxylase ATP + CO2 ADP + Pi Malic acid NADH + H+ NAD+ Aspartate Glutamic acid α-ketoglutarate Aspartate Malic acid Oxaloacetic acid PEP Phosphoenolpyruvate GTP carboxykinase GDP + CO2 Mitochondria Cytosol Only in mitochondria
GLUCONEOGENESISStep 2PyruvateCOATPADPOxaloacetateGTGDPCO.PEPGTPCOO2PGCOOPhosphoenolpyruvate+C=0O=carboxykinase3PG第-8-CH2C0-P-0一COOOCH2OxaloacetatePhosphaenolpyruvateGDPG3PDAP(PEP)C02FBPFGP+G6P→Glucose
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Step 2
ABIOCHEMISTRYANDMOLECULARBIOLOGYStep 2:02-O,PO+ GDP+ GTPC-COOC-COOPEPcarboxykinaseH,C-COOCH,CO.PEPOxaloacetateFIGURE 23.6·The PEP carboxykinase reaction. GTP formed in this reaction can beconverted to ATP by nucleoside diphosphate kinase, although liver cells in some speciesmay not contain this enzyme.Department of Biochemistryand Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Step 2: