In the course of the 1920s and 1930s, great progress was made in the study of the intermediary reactions by which sugar is anaerobically fermented to lactic acid or to ethanol and carbon dioxide.
This oxidation of hydrogen in stages seems to be one of the basic principles of biological oxidation.
Our cells engage in protein production, and many of those proteins are enzymes responsible for the chemistry of life.
I had been impressed by the fact that biological systems were based on molecular machines and that we were learning to design and build these sorts of things.
I feel now, as we did then, that for an effective approach to the problem of nucleic acid biosynthesis, it was essential to understand the biosynthesis of the simple nucleotides and the coenzymes and to have these concepts and methodology well in hand.
The blood pigment haemoglobin is a compound which can be split by diverse methods into its constituents, pigment and protein.
So I set out to study the oxidation system in the potato, which, if damaged, causes the plant to turn brown. I did this in the hope of discovering, through these studies, the key to the understanding of adrenal function.
Coproporphyrin in particular is widespread; traces are present in normal urine and also in yeast. In special cultures, yeast can be made to produce considerable quantities of coproporphyrin.
If we introduce iron complexly into ooporphyrin, we obtain haemin.
We allowed ourselves to become particularly interested in research into the appearance of intermediate products of sugar decomposition during cell-free fermentation.