Answer:
The four stages of cellular respiration could not happen without the one before it; they are: glycolysis, link reaction, krebs cycle and electron transport chain.
Explanation:
Firts of all, in the glycolysis stage, glucose in the cytoplasm is broken into two molecules of pyruvate. Secondly, in the link reaction, pyruvate from glycolysis is pumped into mitochondria; in this stage, one carbon dioxide molecule and one hydrogen molecule are removed from the pyruvate (oxidative decarboxylation) to produce acetyl group which joind to an enzyme called CoA to form acetyl CoA. In the third stage, the kreb cycle stage, acetyl CoA joins with oxaloacetate to form a compound with six carbon atoms. This is the first step in the ever-repeating Krebs cycle; as there are two acetyl-CoA molecules produced from each glucose molecule, two cycles are required per glucose molecule. At the end of this stage, the products are: two ATP, six NADH, two FADH, and four CO2, and the ATP is a molecule that carries energy in chemical form to be used in other cell processes. Finally, in the Electron transport chain stage, most of the ATP is made; all the hydrogen molecules which have been removed in the steps before are pumped inside the mitochondria using energy that electrons release. Eventually, the hydrogen flows back into the cytoplasm of the mitochondria through protein channels, and as the hydrogen flows, ATP is made from ADP and phosphate ions.
