Figure 6.

Metabolism pathways. Extracellular glucose is transported into a cell through the glucose transporter (GLUT), phosphorylated by hexokinase (HK), and converted to glucose-6-phosphate (G6P). Thereafter, G6P is metabolized through either the glycolysis pathway or the pentose phosphate pathway. In the pentose phosphate pathway, G6P is converted to ribose-5-phosphate (R5P), a precursor of nucleotide synthesis, while NADPH is produced as a by-product. In the glycolysis pathway, the final product, pyruvate, is converted to acetyl-CoA, and enters the Krebs cycle in the mitochondria. NADH is generated in the Krebs cycle and used for oxidative phosphorylation where ATPs are produced. On the other hand, citrate generated in the Krebs cycle is released into the cytoplasm where it is converted to acetyl-CoA and then malonyl-CoA. Acetyl-CoA and malonyl-CoA are used for fatty acid production by fatty acid synthase (FASN). Fatty acids are further metabolized to fatty acyl-CoA and used for membrane synthesis, formation of lipid droplets, and signaling lipid production. G6PD; G6P dehydrogenase, 6PG; 6-phosphogluconolactone, F6P; fructose-6-phosphate, F1,6BP; fructose-1,6-bisphosphate, PFK1; phosphofructokinase 1, TIGAR; TP53-induced glycolysis and apoptosis regulator, LDHA; lactate dehydrogenase A, PDH; pyruvate dehydrogenase, PDK; pyruvate dehydrogenase kinase, AIF; apoptosis-inducing factor, SCO2; synthesis of cytochrome c oxidase 2, ACC; acetyl-CoA carboxylase.