Schematic diagram of the biochemical pathways depicting species and metabolic pathways of the cytosol and mitochondria of skeletal muscle. The chemical species are Glc: glucose, Gly: glycogen, G6P: glucose-6-phosphate, F6P: fructose-6-phosphate, F16BP: fructose-1,6-bisphosphate, GA3P: glyceraldehyde-3-phosphate, 13BPG: 1,3-biphosphate glycerate, PEP: phosphoenolpyruvate, Pyr: pyruvate, Lac: lactate, Ala: alanine, Gr3P: glycerol-3-phosphate, Tgl: triglycerides, Glr: glycerol, FFA: free fatty acid, FAC: fatty acyl-CoA, ACoA: acetyl-CoA, Cit: citrate, AKG: α-ketogluterate, SCoA: succinyl-CoA, Suc: succinate, Mal: malate, Oxa: oxaloacetate, CoA: coenzyme-A (free), PCr: phosphocreatine, Cr: creatine, Pi: inorganic phosphate, CO2: carbon dioxide, O2: oxygen, NADH: reduced nicotinamide adenine dinucleotide, NAD+: oxidized nicotinamide adenine dinucleotide, FADH2: reduced flavin adenine dinucleotide, FAD: oxidized flavin adenine dinucleotide, ATP: adenosine triphosphate, ADP: adenosine diphosphate, AMP: adenosine monophosphate, H+: hydrogen ions (protons).