Answer
Carbohydrates, the answer to Buchner's discovery, are organic compounds composed of carbon, hydrogen, and oxygen, primarily serving as an energy source for living organisms. These biomolecules range from simple sugars, like glucose, to complex carbohydrates, like starch and cellulose. Buchner's groundbreaking research unveiled the ability of yeast extracts to ferment sugar in the absence of living yeast cells, revolutionizing our understanding of cellular processes and enzyme activity.