As a follow-up to Lehninger's work several years later, Nishikimi and co-workers observed that the gene that codes for gulonolactone oxidase is actually present in humans, but is not active due to the accumulation of several mutations that turned it into a non-functional pseudogene (Nishikimi & Yagi 1991). Human cells cannot perform the crucial last step of vitamin C biosynthesis, the conversion of l-gulono-g-lactone into ascorbic acid, which is catalysed by the enzyme gulonolactone oxidase. In 1957, the famous biochemist Albert Lehninger studied vitamin C biosynthesis in animals, and realized that, unlike many species, such as cats and dogs, which can biosynthesize their own vitamin C supply, humans are unable to do so. The product of the first reaction becomes the substrate of the second one, and the steps of the pathway run sequentially until the final product is produced (Figure 1). In each step of a biosynthetic pathway, a substrate is converted into a product in a reaction catalysed by an enzyme. Including guinea pigs and humans) have lost the capability to produce it over Therefore surprising that some animals (some fishes and birds, and a few mammals, Neither animals nor plants can live without vitamin C, and it is Why is this molecule so well-known? Apart from itsĭeficiency causing scurvy in humans, vitamin C is also vitally important to Over the next century, what we now know as vitamin C became one of the most Later on, Szent Györgyi and Haworth chemically identified 'C' asĪscorbic acid, and named it so because ascorbic means 'anti-scurvy.' Letter 'C' to designate a factor still unidentified, but known to prevent

Whose deficiencies cause severe diseases in humans. Kazimierz Funk had prepared a list of nutritional factors, called vitamins, Scurvy isĪ pathological life-threatening condition suffered by people who do not haveĪccess to fruits or vegetables for long periods of time. Györgyi, who discovered that it was able to prevent and cure scurvy. Also known as ascorbic acid, vitamin C is a smallĬarbohydrate molecule first identified in the 1920s by Albert von Szent

Albert lehninger