Much as fad diets might tell us to cut them out, energy-packed carbohydrates are essential to most life, thanks to two opposing chemical processes: combustion, which allows us to break down carbs and release energy needed for vital bodily processes, and synthesis, which enables us to use various sugars to build substances we need to live.
Before Argentine physician and biochemist Luis Federico Leloir did his groundbreaking research into the transformation of one sugar into another, combustion was well-understood, but synthesis remained a mysterious, largely guessed-at phenomenon. By isolating a new class of substances called sugar nucleotides, Leloir found the key to deciphering this voluminous backlog of unsolved metabolic reactions. A new field of biochemistry opened up virtually overnight, and Leloir received the 1970 Nobel Prize in chemistry [sources: Myrbäck; Parodi].
Leloir was born in Paris to Argentine parents and lived in Buenos Aires from the age of 2, with the exception of a few years spent abroad. After earning his medical degree from the University of Buenos Aires, he worked at the Institute of Physiology with Bernardo Houssay. In 1947, he established the Institute for Biochemical Research, Buenos Aires, where he began the lactose, or milk sugar, research that would lead to his great breakthrough [sources: Leloir; May].