Otto Heinrich Warburg

Bayliss reported that Warburg and Meyerhof found yeast activity greatly diminished by rubbing with sand, which pointed to structure as essential². Bayliss also listed Warburg's 1910 finding that alkalies, which do not enter the cell, strongly change oxygen consumption, so surface actions mattered³. Thompson drew on Warburg for a wider point. The cell's structure acts as a mechanism that turns the energy of oxidation into work, instead of letting it fall to diffuse heat⁶. Loeb cited Warburg's experiments on the permeability of fertilized sea urchin eggs to salts¹.

Hill summarised work by Warburg and colleagues as showing that many biological oxidations probably occur at surfaces, catalysed by embedded iron atoms. On that view, narcotics could displace the oxidisable substances from those surfaces and hinder oxidation⁵. Lillie reported Usui's work under Warburg's direction. Narcotics lowered oxygen consumption in liver and nervous tissue, but only at much higher concentrations than normal reversible narcosis needs, and the effect was imperfectly reversible⁴. Lillie took this to show that anaesthesia is not necessarily tied to lower intracellular oxidation.

Recent authors use the name Warburg effect for a switch from respiration to respiration plus fermentation despite the presence of oxygen. Schofield and colleagues note it in cancer cells, yeast and bacteria, and call it puzzling because respiration yields more energy per carbon⁷. They propose a bioelectrical reading through redox state and membrane potential, which they say remains to be tested. Carreras-Sureda and colleagues link hypoxia adaptation in solid tumours to the effect, described as reliance on anaerobic glycolysis over oxidative phosphorylation⁸.