A B Cholesterol synthesis Glycogen and galactose metabolism acetyl-CoA x2 1 2 3 4 5 6 8 9 CoA acetoacetyl-CoA acetyl-CoA HMG-CoA synthase CoA glycogen (n) 6 3 4 5 α-1,6 bond Steroid hormone synthesis Zona glomerulosa 2 NADPH HMG-CoA reductase CoA UDP-glucuronate Cholesterol desmolase 17α-hydroxylase pregnenolone 3 ADP CO2 isopentenyl pyrophosphate (IPP) (C5) x3 (multiple steps) 8 NADP (multiple steps) Glycerol-3-phosphate acyltransferase (GPAT) NADPH protein modification NADP+ glycerol ATP ADP Triacylglycerol synthetase complex B12 folate cobalamin 4' 2' 3' 4' glucose-6-phosphate glutamine PPi Glutamine: F6P aminotransferase ATP Phosphofructokinase-1 ADP B6 Coenzyme Q (oxidized) AMP ATP phospholipids 1,2-diacylglycerol Long-chain fatty acyl-CoA synthetase β-ketoacyl-ACP fatty acyl-CoA β-hydroxyacyl-ACP dehydratase palmitate (C16) ADP Acetyl-CoA carboxylase dihydroxyacetone phosphate (DHAP) HCO3 fatty acids ≤ C12 fatty acids > C24 to peroxisomes fatty acids > C14 and < C22 Pi Heme metabolism 4 aspartate tricarboxylate transporter Fatty acid oxidation PPi NAD + NADP+ NADPH malate fatty acyl- CoA fatty acids ≤ C12 Multiple steps Multiple cycles Crosses membrane aspartate Acyl-CoA Synthetase Acyl-CoA dehydrogenases Hydratase CoA Acetyl-CoA synthetase 5 PPi Enzyme cofactor: α-ketoacid dehydrogenases and transketolase Precursor: FAD/FADH2 Hydroxyacyl-CoA dehydrogenases AMP HMG-CoA synthase (in liver) CoA Thiolase Enzyme cofactor: transaminases and other reactions involving amino acids Heme synthesis Enzyme cofactor: carboxylases glycine Single-carbon carrier succinyl-CoA FAD NADH NAD+ CO2 δ-aminolevulinic acid synthase B6 VERSION 10.18 Copyright 2017 Stanford School of Medicine. All rights reserved. This work is licensed under a Creative Commons AttributionNonCommercial-NoDerivatives 4.0 International License. lactate Methylmalonyl-CoA mutase NAD Citric acid cycle (tricarboxylic acid cycle) Pyruvate B1 dehydrogenase CoA Branched-chain ketoacid B1 CO2 dehydrogenase (BCKAD) NAD+ CoA succinyl-CoA succinate acetoacetate acetoacetyl-CoA Succinyl-CoA:acetoacetate β-hydroxybutyrate transferase (SCOT) dehydrogenase (in extrahepatic tissues) Citrate synthase oxaloacetate CoA H2O Propionyl-CoA carboxylase B7 H2O NH4 Fumarase CoA α-ketoglutarate B dehydrogenase 1 Thiolase acetyl-CoA x2 3 H2O2 H2O 3 O2 Protoporphyrinogen IX oxidase Succinyl-CoA synthetase GDP many amino Transaminases acids NADH hydroxymethylbilane uroporphyrinogen III Uroporphyrinogen III Uroporphyrinogen 4 NH4+ synthase decarboxylase D Succinic semialdehyde dehydrogenase CoA Glutamate decarboxylase 2 H2O Coproporphyrinogen oxidase - + + 4H + I - + - + - + - - + - + - + + 2 e- FAD - - - - - - - - - + + + + + + + + + - - 2e CoQ NADH dehydrogenase (Complex I) - GABA aminotransferase + + - - -III - - - - -- - 2e - - - - - 2e - - - + + + + + + + + + + + + + + + + + + ADP Pi - IV + + - NADPH NADP+ + Cytochrome c oxidase (Complex IV) 2 H+ biliverdin + - + - + - - + - + ATP synthase (Complex V) F UDP x2 bilirubin Biliverdin reductase 3 O2 Fe 3+ CO Heme oxygenase UDP-glucuronate x2 Pi Ornithine transcarbamoylase (OTC) ornithine H2O Nucleotidase Pi AMP deaminase + 3 H+ + - + - - phosphate transporter + + Pi - - - - - H2O adenine nucleotide transporter + + + ADP + NH4+ + Nucleotidase (deoxy) ribose-1-P (deoxy) adenosine Adenosine deaminase H2O Guanine deaminase conjugated bilirubin UDP-glucuronyltransferase G B6 sulfite (SO3 ) Sulfite oxidase taurine bile salts Xanthine oxidase feces urine bile NH4 UTP ATP CTP synthetase ADP + Pi aminoiminidazole carboxamide ribonucleotide (AICAR) N10-formyl-THF AICAR transformylase urea IMP cyclohydrolase arginine NH4+ H2O Nucleotidase adenylosuccinate pyrroline-5-carboxylate PRPP Adenine phosphoribosyltransferase AMP (deoxy) inosine Thymidine phosphorylase Pi (deoxy) ribose-1-P NADPH NADP+ β-ureidopropionate CO2 ATP adenine guanine PRPP ATP GMP synthetase glutamate HGPRT PRPP AMP + PPi GMP PPi ATP ADP PRPP synthetase ATP ribose-5-P GTP GMP kinase ADP GDP Phosphopentomutase Nucleoside diphosphate kinase glutamine AMP ADP UDP Pi ATP Kinase ADP deoxy ribose-1-P dCDP ATP Kinase ADP ribose-1-P uracil Pi Uridine phosphorylase GDP dATP NH4 β-alanine dCTP dGTP Phosphatase NADP+ H2O Pi ATP uridine ADP 5 Nucleoside diphosphate kinase thioredoxin (reduced) β-ureidoisobutyrate NH4 (spontaneous) dUTP pyrophosphatase Thioredoxin reductase NADH, FADH2 dUTP ATP ADP adenosine NADPH Thymidylate synthase (TS) dUMP adenosine 5’-monophosphate (AMP) dTMP 10 SHMT uridine dTDP Kinase dihydrofolate ATP DHFR ADP glycine Uridine-cytidine kinase cytidine 5’-monophosphate (CMP) uridine 5’-monophosphate (UMP) ATP ADP Kinase NADP+ deoxycytidine Deoxycytidine kinase deoxycytidine 5’-monophosphate (dCMP) ATP ADP NADPH THF serine cytidine ATP ADP ATP ADP N ,N methylene-THF 5 Ribonucleotide reductase Adenosine kinase Nucleoside salvage ATP ADP PPi NADP+ thioredoxin (oxidized) β-aminoisobutyric acid Deoxynucleotide deaminase GTP biopterin Coenzyme A ATP Kinase ADP NH4+ dCMP + S-adenosyl methionine NH4+ NADPH CO2 ATP dUDP ATP Kinase ADP dihydrothymine Ureidopropionase + I H2O Phosphatase Pi CDP dGDP Dihydropryimidinase H2O2 H2O Phosphatase Pi GDP dADP thymine Dihydropyrimidine dehydrogenase (DPD) dihydrouracil H2O UTP (deoxy) ribose-1-P uracil H2O2 CTP H2O Phosphatase Pi ADP thymidine (deoxy) uridine Pi O2 GTP H2O Phosphatase Pi deoxyTMP H2O H2O Nucleotidase Pi Pi Adenylate kinase Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) hypoxanthine NADP+ Pyrroline-5-carboxylate reductase NADP+ GMP reductase NADPH XMP PPi proline 4 + Uridine phosphorylase H2O NAD+ IMP dehydrogenase NADH fumarate UMP (deoxy) cytidine Pyrimidine nucleoside deaminase H2O H2O Base salvage H2O pyrroline5-carboxylate NH4+ Adenylosuccinate GTP synthetase GDP Pi AMP NADPH CTP inosine monophosphate (IMP) Adenylosuccinate lyase (spontaneous) glutamate aspartate asparagine fumarate (spontaneous) H2O α-ketoglutarate PPi NH4+ glutamine formaminoimidazole carboxamide ribonucleotide (FAICAR) ATP 3 Adenylosuccinate lyase sulfate (SO42-) NH4+ AMP deaminase Nucleoside diphosphate kinase NH4 + uric acid H ATP fumarate aspartate ATP H2O Pi Xanthine oxidase xanthine ATP UDP H2O 2- glutamate Transaminase NH4+ Asparaginase H2O Argininosuccinate lyase NADPH Arginase ornithine Pi (deoxy) IMP ATP ADP Pi - glutamate Deoxyribonucleotides Nucleotidase Pi guanine ADP SAICAR synthetase ADP pyruvate β-sulfinylpyruvate glutamine Asparagine synthetase glutamate ornithine/citrulline transporter (deoxy) CMP Purine nucleoside phosphorylase - B6 oxaloacetate argininosuccinate O2 glutamic semialdehyde (deoxy) AMP (deoxy) guanosine Purine nucleoside phosphorylase UMP kinase aspartate ADP NADH NADP+ H2O Pi hypoxanthine - hypotaurine Nitric oxide synthase RNA/DNA H2O + TCA ATP Pi Transaminase Hypotaurine dehydrogenase AMP citrulline Pi NADPH NADP+ Pyrroline-5carboxylate synthetase Pi urea cycle (regulation) V CO2 Argininosuccinate synthetase PPi ATP NO glutamate ATP ADP + Pi 2 H+ - H2O uridine-5'-monophosphate (UMP) succinylaminoimidazole carboxamide ribonucleotide (SAICAR) α-ketoglutarate NAD+ ornithine/citrulline transporter ATP ADP O2 3 NADPH 3 NADP+ creatinine (excreted) citrulline Ornithine aminotransferase B6 aspartate Dehydrogenase Nucleotidase 3 H+ B6 Cytochrome c reductase (Complex III) 4 H+ heme b E - Cysteine sulfinite decarboxylase (spontaneous) H2O oxaloacetate (deoxy) GMP acetate H2O Hydrolase γ-aminobutyric acid (GABA) Cyt c Succinate dehydrogenase (Complex II) Heme degradation coproporphyrinogen III - CO2 α-ketoglutarate /2 O2 + 2H FADH2 II - - - - - Creatine kinase polyamines Nucleotide breakdown N-acetylglutamate Oxidative phosphorylation 4 H+ succinate I phosphocreatine succinyl-CoA OMP decarboxylase (UMP synthase) CO2 CO2 ATP PPi N-acetylglutamate synthase acetyl-CoA CoA 1 protoporphyrinogen IX 4 CO2 succinic semialdehyde NADH NAD ADP ATP 2 ADP Hydratase glutamine many α-ketoacids B6 glutamate NAD+ GTP + Pi B6 NH4+ H2O ATP Glutamine synthetase NH4 cysteine sulfinate Nucleases Glutaminase NH4+ H2O nucleotide salvage Threonine dehydratase + threonine SAM orotidine-5'-monophosphate (OMP) aminoimidazole ribonucleotide (AIR) Thiolase acetyl-CoA x2 TCA O2 Cysteine dioxygenase acetoacetyl-CoA CoA NADH NAD Glutamate dehydrogenase-1 NADH succinyl-CoA Pi 4 H+ ornithine ATP Pi H2O cysteine Coenzyme A 2 ATP NADH glutamate NAD+ CO2 2 H+ CoA Methylmalonyl-CoA mutase B12 + fumarate glutathione Orotate phosphoribosyltransferase PPi ADP (in mitochondrial matrix) α-ketobutyrate HCO3 carbamoyl phosphate 2 orotate AIR synthetase - Carbamoyl phosphate synthetase I (CPS1) Dihydroorotate dehydrogenase (in mitochondria) NADH carboxyaminoimidazole ribonucleotide (CAIR) Cystathionine γ-lyase B6 porphyrins arginine crotonyl-CoA NAD+ succinyl-CoA α-ketoglutarate HCO3 NH4 + β-hydroxybutyryl CoA methylmalonyl-CoA Ammonium capture and release + - propionyl-CoA Propionyl-CoA carboxylase B7 ADP AIR carboxylase Urea cycle Glutaryl-CoA dehydrogenase H2O NAD+ THF glutaryl-CoA odd-chain fatty acyl-CoA (last three carbons only) HCO3- ADP acetyl-CoA acetoacetate NADH CO2 ATP CoA NAD Isocitrate dehydrogenase NADH FAD HMG-CoA lyase + B1 dihydroorotate formiminoglycinamidine ribonucleotide (FGAM) cystathionine B6 CoA α-ketoadipate B1 dehydrogenase CO2 FADH2 ATP β-methylcrotonyl-CoA carboxylase B7 isocitrate ADP NADH NAD+ isobutyryl-CoA propionyl-CoA º-hydroxy-β-methylglutaryl-CoA (HMG-CoA) Aconitase B1 CoA BCKAD CO2 acetyl-CoA β-methylglutaconyl-CoA hydratase H2O NAD+ CH3 (used for methylation) adenosine serine (spontaneous) Transaminase Dihydroorotase PRPP homocysteine nucleotides SAH N-carbamoyl aspartate H2O glutamine S-adenosylhomocysteine (SAH) Cystathionine β-synthase B6 creatine α-ketoadipate (multiple steps) β-methylglutaconyl-CoA H2O Aconitase Methylene-THF reductase NADH α-aminoadipate glutamate α-ketoisovalerate α-methylbutyryl-CoA HCO3- ADP methylmalonyl-CoA O2 H2O NADH β-methylcrotonyl-CoA citrate CoA BCKAD CO2 NAD+ Isovaleryl-CoA dehydrogenase NADH Ferrochelatase C α-ketoisovalerate α-keto-β-methylvalerate isovaleryl-CoA Fe2+ protoporphyrin IX PBG deaminase B6 glutamate α-keto-β-methylvalerate α-ketoisocaproate NAD+ B12 NADH FGAM synthetase S-adenosylhomocysteine hydrolase glutathione Guanidinioacetate methyltransferase (GAMT) N10-formyl-THF formyl-GAR (FGAR) 3 Pi N5-methyl-THF α-ketoglutarate malate + TCA H2O Transaminase B6 glutamate SAH Pi THF Homocysteine B12 methyltransferase guanidinoacetate α-aminoadipic semialdehyde NAD+ Dehydrogenase NAD+ Malate dehydrogenase succinyl-CoA 2 CO2 δ-ALA x2 porphobilinogen (PBG) x4 δ-ALA dehydratase glutamate heme b β-hydroxybutyrate 2 H2O NADP saccharopine NAD+ Saccharopine NADH dehydrogenase glutamate Transaminase B6 cis-aconitate NAD protoporphyrinogen IX B Lactate dehydrogenase glycinamide ribonucleotide (GAR) S-adenosylmethionine (SAM) NAD+ Amidinotransferase (in mitochondrial matrix) Aspartate transcarbamoylase aspartate Pi NADP+ glycine Lysine-αketoglutarate reductase + α-ketoglutarate Transaminase SAM carbamoyl phosphate ADP TCA NADH Glycine cleavage complex THF α-ketoglutarate valine α-ketoglutarate α-ketoglutarate CO2 NADH oxaloacetate - Email questions or comments to: metabolicpathways@stanford.edu ATP + dehydrogenase δ-aminolevulinic acid (δ-ALA) NH4+ NADPH isoleucine leucine Alanine B6 transaminase (ALT) pyruvate NAD+ ADP NADH 6 Pathways of Human Metabolism ADP CoA 1 ATP Pi melatonin Pi 2 ADP 5-phosphoribosylamine glutamate N5,N10-methylene-THF Methenyl-THF reductase lysine alanine acetone NADH serine glutamate NADH ATP FADH2 β-hydroxybutyrate + N5,N10-methenyl-THF Pi H2O Hydroxyindole O-methyltransferase Carbamoyl phosphate synthetase II (CPSII) glutamate glutamate GAR transformylase methionine NADPH Serine hydroxymethyltransferase (SHMT) B6 Branched chain amino acid breakdown α-ketoglutarate NADH TCA H2O acetyl-CoA pyrimidine synthesis NADPH NADP+ Methenyl-THF cyclohydrolase sphingosine cholesterol (cytosol) (spontaneous) 3-phosphoserine α-ketoglutarate ATP (n-2) fatty acyl-CoA acetyl-CoA NAD CoA Enzyme cofactor: methylmalonyl-CoA mutase and homocysteine methyltransferase acetoacetate N10-formyl-THF ceramide (long chains only) CO2 acetyl-CoA B6 N-acetyl-5-HT Methyltransferases H2O phosphatidylserine CoA (odd-chain fatty acids only) HMG-CoA lyase (in liver) TCA Precursor: CoA glutamate Serotonin N-acetyltransferase 2 ATP ATP fumarate histidine catabolism ADP Pi C1-THF synthase Phosphoserine phosphatase Translocase β-ketoacyl-CoA β-hydroxy-β-methyl-glutaryl-CoA (HMG-CoA) Precursor: NAD+/NADH and NADP+/NADPH fatty acyl-carnitine β-hydroxyacyl-CoA acetoacetyl-CoA acetyl-CoA glutamate (many cycles) ATP acetyl-CoA 3-phopsphopyruvate NADH NAD+ Pyruvate B7 carboxylase B6 CPT1 fatty acyl-CoA NADH CoA Phosphoserine transaminase acetyl-CoA Fatty acyl-CoA synthetase Thiolase Phosphoglycerate dehydrogenase pyruvate HCO3- α-ketoglutarate acetyl-CoA x2 acetate acetoacetate CO2 ATP mitochondrial pyruvate carrier dicarboxylate transporter trans-enoyl-CoA NAD+ DHFR VMA Fumarylacetaoacetate hydrolase H2O ADP CO2 PPi acetaldehyde Acetaldehyde dehydrogenase tetrahydrofolate (THF) α-ketoisocaproate AST Ketone body metabolism Participates in additional reactions dihydrofolate Dihydrofolate reductase (DHFR) NADH Pyruvate kinase Malic enzyme CoA CPT2 acetaldehyde folate α-ketoglutarate glutamate/ aspartate transporter citrate (spontaneous) ATP AMP B9 ATP formate vanillylmandelic acid (VMA) Methionine adenosyltransferase TCA NADPH NADP+ PPi SAH 5-hydroxyindoleacetic acid THF phosphoenolpyruvate Phosphoenolpyruvate carboxykinase NADH Malate dehydrogenase Aspartate aminotransferase B6 (AST) CoA BH2 Dihydrobiopterin reductase xylulose-5-phosphate (step 1) SAM Monoamine oxidase (MAO) fumarylacetoacetate α-ketoadipate Long-chain fatty acyl-CoA synthetase CoA (spontaneous) CO2 B1 BH4 HCO3- glutamine GAR synthetase CO2 NADPH Pyrimidine synthesis glutamine Glutamine PRPP amidotransferase (GPAT) epinephrine H2O serotonin (5-HT) niacin Single-carbon metabolism and sulfur-containing amino acids 2-phosphoglycerate 2,3-bisphosphoglycerate 2,3-bisphosphoglycerate phosphatase Enolase H2O CO2 GTP GDP glutamate citrate carnitine NADH GTP O2 Aromatic amino acid decarboxylase B6 (DOPA decarboxylase) 5-hydroxytryptophan Maleylacetoacetate isomerase (spontaneous) CO2 ATP 3-phosphoglycerate Pi dehydrogenase 3 glyceraldehyde3-phosphate (step 2) NAD+ Glyceraldehyde-3phosphate dehydrogenase oxaloacetate ADP Citrate lyase ATP lysine ethanol NAD+ Alcohol 4 + 5 B1 + Phosphoglycerate mutase Pi acetyl-CoA Pi carnitine transporter Nucleotides 6 erythrose4-phosphate NADPH NADP+ Bisphosphoglycerate mutase CO2 - Fatty acid synthase ATP AMP succinylacetoacetate glyceraldehyde3-phosphate Triosephosphate isomerase Triose kinase ADP ATP Malonyl-CoA decarboxylase ATP NADPH CoA H2O norepinephrine homovanillic acid (HVA) H2O Tryptophan hydroxylase NADP Methyltransferase glycine tryptophan Homogentisate dioxygenase Dopamine β-hydroxylase dopamine BH2 Dihydrobiopterin reductase O2 maleylacetoacetate 1,3-bisphosphoglycerate trans-enoyl-ACP Enoyl-ACP reductase Ribulose-5phosphate epimerase BH4 + GTP-cyclohydrolase purine synthesis CoA ACP H2O O2 formate ribose-5-phosphate Tyrosine hydroxylase NADP+ NADPH homogentisate (spontaneous) M 5-phosphoribosyl pyrophosphate (PRPP) Aromatic amino acid decarboxylase B6 (DOPA decarboxylase) Aldolase malonyl-CoA Pi Acetyl-CoA ACP transacylase alkapton Dihydroneopterin triphosphate ribulose-5-phosphate B6 p-hydroxyphenylpyruvate dioxygenase CO2 CO2 Ribose-5phosphate isomerase 7 5 + + Transketolase 3 5 O2 succinylacetone FADH2 NADP+ β-hydroxyacyl-ACP CoA B7 CO2 NADPH β-ketoacyl-ACP reductase ATP H2O dihydroxyphenylanine (L-DOPA) p-hydroxyphenylpyruvate (multiple steps) (step 3) glyceraldehyde ACP acetyl-ACP AMP 5-phosphoribosyl pyrophosphate (PRPP) Dihydrobiopterin (BH2) Dihydrobiopterin reductase NADP+ NADPH 6-Phosphogluconate dehydrogenase O2 Transaminase glutamate L Purine synthesis α-ketoglutarate Tetrahydrobiopterin (BH4) 6-phosphogluconate (multiple steps) tyrosine α-ketoglutarate K melanin Tyrosinase (multiple steps) H2O Phenylalanine hydroxylase phenylalanine H 6 7 + + Transaldolase 4 3 fructose-1,6-bisphosphate Fructose-1-P aldolase (aldolase B) fructose-1-phosphate Malonyl-CoA ACP transacylase β-ketoacyl-ACP synthase H2O glutamate B6 + sedoheptulose7-phosphate Transketolase ADP CO2 ACP phenylpyruvate O2 J dopaquinone triiodothyronine (T3) thyroxine (T4) NADP+ NADPH PRPP synthetase Pi Fructose-1,6bisphophatase Transaminase NADP+ NADPH Lactonase Phosphomannose isomerase fructose-6-phosphate mannose-6-phosphate Hexokinase NAD NADH Fructokinase (first cycle only) ACP Glutathione peroxidase 2 H2O 6-phosphogluconolactone nucleotides Phosphoglucose isomerase Dehydrogenase phenyllactate biosynthetic reduction reactions Glucose-6-phosphate dehydrogenase (G6PD) Phosphoglycerate kinase malonyl-ACP NADPH NADP+ ATP (multiple steps) H2O2 Glutathione reductase glutathione (oxidized) ADP Amino acids Vitamins B9 3' sphingolipids sphingosine carnitine Plasma membrane biotin 4 + ATP CoA free fatty acids Inner mitochondrial membrane B7 3 Glycerol-3-phosphate dehydrogenase glycerol 3-phosphate fructose CO2 CoA Outer mitochondrial membrane B6 2' Fatty acid synthesis (7 cycles) free fatty acids Lipids pyridoxal phosphate 2 glucosamine- 6-phosphate NADPH β-ketoacyl-ACP synthase Pi Oxidative metabolism pantothenate Glycerol kinase palmitoyl-CoA CoA H2O Carbohydrates niacin 4 Phosphofructokinase-2 Fructose bisphosphatase-2 (Bifunctional enzyme) FAD fatty acyl-ACP phosphatidic acid Legend riboflavin 3 ADP estradiol NAD NADH (multiple steps) CoA Diet B2 B3 B5 1 glutamate CoA formate lipoproteins (extrahepatic metabolism) thiamine 2 (in mitochondrial matrix) (n+2) fatty acyl-ACP B1 0 Coenzyme Q (reduced) NADP+ thin gray arrow 1 glutathione (reduced) I Aromatic amino acid metabolism phenylacetate ATP ADP estrone dihydrotestosterone (DHT) NADP+ triacylglycerol heavy gray arrow Hexokinase or glucokinase fructose Pentose phosphate pathway Glucose-6-phosphatase (in endoplasmic reticulum) ATP H NADH NAD+ fructose 2,6-bisphosphate mannose Galactokinase (in peripheral tissue) glycerol-3-phosphate protein modification cell lipoproteins bile salts (liver) membranes gray dashed arrow -1 ATP galactose Aldose reductase + 11β-HSD1 serine cholesterol black dashed arrow ADP 17β-HSD Aromatase 4 α-1,6-Glucosidase (in lysosomes) Galactose-1-phosphate uridyltransferase (GALT) GAGs Aromatase 3 + + 7-Dehydrocholesterol reductase 0 NADP+ Glycolysis and Gluconeogenesis Lactose synthase (inside Golgi of mammary cells) cortisone 7-dehydrocholesterol vitamin D (skin) 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) (in adrenal cortex, some in gonad) 8 NADPH 2 CO2 galactitol 5α reductase aldosterone 10 O2 4 NADH -2 glucose-1-phosphate glycosaminoglycans (GAGs) glycoproteins NADP+ NADPH glycolipids androstenedione 17β-hydroxysteroid dehydrogenase (17β-HSD) 2 Mitochondrial glycerol 3-phosphate dehydrogenase (flavoprotein) Aldosterone synthase lanosterol 4 NAD+ -1 galactose-1-phosphate testosterone cortisol NADPH -2 -3 UDP-galactose glucose + dehydroepiandrosterone (DHEA) 3β-hydroxysteroid dehydrogenase 1 Phosphoglucomutase 11β-hydroxylase corticosterone squalene (C30) NADP 11-deoxycortisol 11β-hydroxylase NADP+ (multiple steps) 17, 20 lyase 21-hydroxylase (not in gonad) 11-deoxycorticosterone (11-DOC) NADPH 2 PPi 17-hydroxyprogesterone 21-hydroxylase (not in gonad) farnesyl pyrophosphate (FPP) (C15) x2 Squalene synthase 3β-hydroxysteroid dehydrogenase 17α-hydroxylase progesterone 17, 20 lyase 17-hydroxypregnenolone 3β-hydroxysteroid dehydrogenase 2 PPi 2 NAD -3 -4 -5 UDP lactose Zona fasciculata and zona reticularis 3 ATP (multiple steps) 3 2 NADH 0 1 Glucose 1' (free) UTP glucoseUTP 1-phosphate uridyltransferase UDP UDP-glucose dehydrogenase cholesterol 2 NADP+ mevalonate 2 glycogenin -4 -5 UDP-galactose epimerase UDP-glucose -1 1' glycogen (n) primed glycogenin (8 cycles) -2 4:4 Transferase PPi other glucuronidation reactions β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) -3 G Sorbitol dehydrogenase sorbitol Pi 1' -4 -5 UDP conjugated bilirubin NADPH 3' 2' UDP-glucose 7 Aldose reductase 4' Debranching enzyme Glycogen phosphorylase Glycogen synthase F glucose B6 (many cycles) 8 2 Pi 10 9 E (branch point only) (debranching) glycogen (n+1) (branching) 7 10 Glycosyl (4:6) transferase (branching 1 enzyme) D (many cycles) α-1,4 bonds Thiolase 1 C thymidine deoxyuridine dTTP Thymidine kinase deoxythymidine-5'-monophosphate (dTMP) deoxyuridine 5’-monophosphate (dUMP) ATP ADP J K L M 6