Pentose phosphate pathway - Homo sapiens (human)

Curator(s): Joe Strothman

The pentose phosphate pathway is a process of glucose turnover that produces NADPH as reducing equivalents and pentoses as essential parts of nucleotides. There are two different phases in the pathway. One is irreversible oxidative phase in which glucose-6P is converted to ribulose-5P by oxidative decarboxylation, and NADPH is generated. The other is reversible non-oxidative phase in which phosphorylated sugars are interconverted to generate xylulose-5P, ribulose-5P, and ribose-5P. Phosphoribosyl pyrophosphate (PRPP) formed from ribose-5P is an activated compound used in the biosynthesis of histidine and purine/pyrimidine nucleotides. This pathway map also shows the Entner-Doudoroff pathway where 6-P-gluconate is dehydrated and then cleaved into pyruvate and glyceraldehyde-3P.    
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Pentose phosphate pathway - Homo sapiens (human) Glycolysis node2 Beta -D -Glucose Glycolysis->node2 node3 D-Glucose Glycolysis->node3 node4 Alpha -D -Glucose-6P Glycolysis->node4 node1 Amino sugar and nucleotide sugar metabolism - Homo sapiens (human) node60 D-Glucisaminate node1->node60 Histidine metabolism Purine metabolism Pyrimidine metabolism node15 node2->node15 node16 node2->node16 node17 node3->node17 node18 node3->node18 node5 Beta -D -Fructose-6P node29 node5->node29 node6 Beta -D -Fructose-1,6P2 node27 node6->node27 node7 D-Glyceraldehyde -3P node7->Glycolysis node8 D-Glucono -1,5-lactone node19 node8->node19 node9 D-Gluconate node20 node9->node20 node23 node9->node23 node25 node9->node25 node10 2-Dehydro -D-gluconate node22 node10->node22 node11 2-Dehydro -D-gluconate -6P node24 node11->node24 node12 Beta -D -Glucose-6P hexose-6-phosphate dehydrogenase (glucose 1-dehydrogenase) H6PD node12->H6PD node49 node12->node49 node13 D-Glucono -1,5-lactone -6P node50 node13->node50 node14 node14->node2 node14->node8 node15->node8 node16->node8 node17->node8 node18->node8 node19->node9 node20->node10 node21 node21->node9 node21->node10 node22->node11 node52 6-Phospho -D-gluconate node23->node52 node24->node52 node67 2-Dehydro -3-deoxy -D-gluconate node25->node67 node26 node66 2-Dehydro -3-deoxy -D-gluconate -6P node26->node66 node27->node5 node28 2 node29->node6 node29->node28 node30 node30->node5 node30->node7 node53 D-Xylulose -5P node30->node53 node55 D-Sedo -heptulose-7P node30->node55 node59 D-Erythrose -4P node30->node59 node61 D-Ribose -5P node30->node61 node31 node31->node5 node31->node7 node31->node55 node31->node59 node32 node32->node53 node54 D-Ribulose -5P node32->node54 node33 node33->node54 node33->node61 node34 PRPP node34->PRPP node34->node61 node35 node35->node6 node35->node7 node36 node36->node7 node37 node37->node7 node56 2-Deoxy -D-ribose -5P node37->node56 node38 node38->node56 node57 2-Deoxy -D-ribose node38->node57 node38->node61 node62 D-Ribose node38->node62 node39 node39->node56 node58 2-Deoxy -D-ribose -1P node39->node58 node39->node61 node63 D-Ribose -1P node39->node63 node40 node40->node67 node41 4.1.2.- node41->node7 Pyruvate node41->Pyruvate node41->node66 node41->node67 node68 D-Glyceraldehyde node41->node68 node42 Glycerate node42->Glycerate node43 2.7.1.- node69 Glycerate-2P node43->node69 node44 node44->node7 node44->Pyruvate node44->node66 node45 node45->PRPP node46 node46->node61 node46->node63 node47 node47->node4 node47->node5 node47->node12 H6PD->node52 node48 1 node49->node13 node49->node48 node50->node52 node51 node51->node54 node52->node26 node52->node51 node53->node36 PRPP->Histidine metabolism PRPP->Purine metabolism PRPP->Pyrimidine metabolism node60->node40 node64 D-Ribose -1,5P node63->node64 node64->node45 node65 2 Pyruvate->Glycolysis Pyruvate->node65 Pyruvate node70 node67->node70 node68->node42 Glycerate->node43 node69->Glycolysis node70->node66 print "