STUDIES ON THE OXIDATION OF CERTAIN FATTY ACIDS

Abstract

In both plant and animal bodies, under certain conditions, sugars are changed to fats ; and in the plant, if not in the animal, these fats are converted back to sugars for use when a certain other set of conditions is provided. These are well known facts of physiology. It is pretty well established that the point of departure is the fatty acid ; that is, the fatty acid is formed before the neutral fat, and the neutral fat is hydrolized to fatty acid and glycerol before being changed to sugar. Thus we may consider the changes as one between fatty acid and sugar for our present purposes. This reversible transformation is one that is very common and widespread in the plant kingdom, not to mention the animal world. Great quantities of food are put through this process, especially in the ripening and germination of fatty seeds. In these cases the carbon is conducted as a soluble carbohydrate and then stored in the lighter, more compact, and insoluble form of fat. Before being transportable again and ready for use in other parts of the plant it must be made soluble again ; the common transport material of the fatty seedling is sugar. But these very common food transformations are not understood. We know that at one time we have sugar and at another, fat, or vice versa ; but we do not understand how* this remarkable change can be so generally brought about especially at the normal air temperatures. This general biological interchangeability of fats and sugars has no chemical parallel, nor have chemists been able to point out the manner in which such a transformation can be made, although it is a question of much simpler compounds, structurally, than some that have been successfully dealt with in the laboratory. Of course, we know that the formation of the fatty acid requires a reduction of the carbon atom, and the change back to sugar is an oxidation process ; and we know further that in so changing, it has attached an atom of oxygen per carbon atom. Anything further on the intermediate steps is purely hypothetical and not supported by evidence. The fact that enzymes have been isolated which are found to aid in the reactions of many of the known plant processes, naturally suggests that there may be one or more enzymes responsible for the changes here under consideration. It must be remembered, however, that there is probably much to protoplasmic activity that is not to be detached, so to speak, not