Question

Fermentation is considered to be the oldest existing method of cellular respiration. The fact that glycolysis occurs in all known cells supports this hypothesis. It is not known how glycolysis evolved, but it is unlikely that it was the first method of respiration, as it is complex and as it exists today is catalyzed by a large number of complex enzymes. Furthermore, it creates a chicken-egg problem in that these proteins require ATP for glycolysis to take place in the first place! This suggests that early respiration was either a less efficient form of glycolysis that did not require external