History of

Apuntes

•Introduction Enzymes catalyze nearly all physiological reactions essential for life and have been extensively studied since the late nineteenth century, following the resolution of vitalism debates. Their history, however, begins over a century earlier, with Lazzaro Spallanzani's 1780 demonstration that food digestion was a chemical process, not primarily dependent on grinding. •Vitalism Throughout the nineteenth century, digestion and other physiological processes were attributed to substances called ferments, due to their role in alcoholic fermentation. Wilhelm Kühne (1877) coined the term enzyme (meaning "in yeast"), which replaced earlier terminology. Spallanzani’s findings that digestion could occur outside organisms challenged vitalism—the idea that life chemistry depends on a vital force. Yet, debates persisted until Eduard Buchner (1897) showed that a cell-free yeast extract could catalyze fermentation. The controversy was complicated by some scientists, like Justus von Liebig, who denied yeast's status as a living organism and argued fermentation required no vital force, while Louis Pasteur believed a vital force was necessary, based on experiments with top-fermentin...