56 pathways across 7 categories. Open any one for its full ordered reaction list, regulation table and clinical notes.
Transamination is the reversible transfer of an α-amino group from an amino acid to an α-keto acid. It funnels nitrogen from most amino acids onto glutamate, while producing carbo…
Open pathwayThe urea cycle converts toxic ammonia and the amino nitrogen of aspartate into urea, the principal nitrogenous waste product in humans. It is essential during amino-acid catabolis…
Open pathwayDeoxyribonucleotide formation converts ribonucleotide pools into the balanced deoxyribonucleoside triphosphate (dNTP) pools required for faithful DNA replication and repair. Ribon…
Open pathwayPurine de novo synthesis constructs the purine ring atom-by-atom on ribose 5-phosphate, generating inosine monophosphate (IMP), the common precursor of AMP and GMP. The pathway su…
Open pathwayHumans degrade purine nucleotides to uric acid (present predominantly as urate at physiologic pH), which is excreted mainly by the kidney and, to a lesser extent, the intestine. U…
Open pathwayPurine salvage conserves preformed purine bases and nucleosides by reconverting them into nucleotides, thereby avoiding the high energetic cost of de novo synthesis. It is particu…
Open pathwayPyrimidine de novo synthesis first constructs the six-membered pyrimidine ring and then attaches it to PRPP, in contrast to purine synthesis, which builds the ring directly on rib…
Open pathwayPyrimidine nucleotides are degraded to highly water-soluble, small metabolites rather than to a poorly soluble terminal product such as urate. Uracil yields beta-alanine, whereas …
Open pathwayAnaerobic glycolysis converts glucose to pyruvate and then reduces pyruvate to lactate, regenerating cytosolic NAD+ so glycolytic ATP production can continue when mitochondrial ox…
Open pathwayThe citric acid cycle (TCA cycle, Krebs cycle) oxidizes the acetyl group of acetyl-CoA to two molecules of CO2 while capturing reducing equivalents as NADH and FADH2 and generatin…
Open pathwayThe mitochondrial electron transport chain (ETC) transfers electrons from NADH and FADH2 to molecular oxygen through a sequence of redox carriers while using the released free ene…
Open pathwaySkeletal muscle, brown adipose tissue, brain
Open pathway