Energy production in cells

Cells gain energy through a number of pathways that generate ATP. The first pathway in this process is called glycolysis. This process has many reactions in it, though essentially a molecule of glucose is oxidized using NAD+. The end product of glycolysis is NADH, 2 ATP and 2 Pyruvate. The pyrvate then enters the next stage, where it is transformed into Acetyl-CoA. Acetyl-CoA formation also requires NAD+ and produces NADH and CO2. Once Acetyl-CoA is produced it may enter the krebs cycle. The Krebs cycle fully oxidizes Acetyl-CoA into CO2 an H20. This process produces a total of 8-NADH, 2-FADH2 and 2-ATP per glucose molecule. Taking into account glycolysis, acetyl-CoA formation and the krebs cycle producs a total of 10-NADH, 2-FADH2 and 4-ATP. The ATP produced is of course free to be used by the cell. However, the NADH and FADH2 are used to power the electron transport chain and further ATP synthesis.