BIOCHEMISTRYANDMOLECULARBIOLOGYAlternatereactionsStep 1 and 2:Pyruvate---oxaloacetate---phosphoenolpyruvate(PEP)Step 3: Fructose 1,6-bis-p --- Fructose 6-pStep 4: Glocose 6-p --- GlucoseDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Step 1 and 2: Pyruvate-oxaloacetate-phosphoenolpyruvate(PEP) Step 3: Fructose 1,6-bis-p - Fructose 6-p Step 4: Glocose 6-p - Glucose Alternate reactions
Step 1 and 2:Pyruvate---oxaloacetate(OAA)---phosphoenolpyruvate(PEP)Carboxylation ofpyruvateThe first roadblock"" to overcome in the synthesis of glucosefrom pyruvate is the irreversiblee conversion of pyruvatetoPhosphoenolpyruvate (PEP) by pyruvate kinase.Phosphoenolpyruvate→2LactatePyruvateCO2Oxaloacetate
Carboxylation of pyruvate The first “roadblock” to overcome in the synthesis of glucose from pyruvate is the irreversible conversion of pyruvate to Phosphoenolpyruvate (PEP) by pyruvate kinase. Step 1 and 2: Pyruvate-oxaloacetate(OAA)-phosphoenolpyruvate(PEP)
BIOCHEMISTRYANDMOLECULARBIOLOGYStep 1 and 2:> In gluconeogenesis, pyruvate is first carboxylated bypyruvate carboxylase to Oxaloacetate (OAA)> OAA is then converted to phosphoenolpyruvate (PEP) bythe action of PEP carboxykinasePhosphoenolpyruvate+2LactatePyruvateCO1OxaloacetateDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY ➢ In gluconeogenesis, pyruvate is first carboxylated by pyruvate carboxylase to Oxaloacetate (OAA) ➢ OAA is then converted to phosphoenolpyruvate (PEP) by the action of PEP carboxykinase. Step 1 and 2:
Thisreaction occurs inthe ERPluicoseATPChucose-b-phosphataseADPelATPUCLOSR31phospiataseFTiciOse16LbislHOADPDihydroxyaeeraldehyde-s-pNADNAD个NADHNADHGlycerolL,8-BisphosphoglycerateGluconeogeneis00ADPADATPP3-phosphogl1JT2-PhosphoglatGDPPEPczirboxykinaPEPADPGTPxaloacetaLeMiitochondrialATPPuvateDPPTpyruvateAIPKVMIJAminoacidsLactate
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
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