From the secret of fermentation to "enzyme"
In 1833 the French chemists Anselme Payen and Jean-François Persoz extracted from malt a substance that turned starch into sugar and called it diastase — the first enzyme isolated. Louis Pasteur then held that fermentation required living yeast cells. In 1877 the German physiologist Wilhelm Kühne coined "enzyme", from the Greek for "in yeast", and in 1897 Eduard Buchner showed that juice pressed from ground yeast could ferment sugar on its own, ending the "vital force" debate and earning the 1907 Nobel Prize. In 1926 James Sumner crystallised urease, proving that enzymes are proteins.
How enzymes work
Every reaction has an energy hill to climb — the activation energy — and enzymes lower it, speeding reactions by a million times or more. In 1894 Emil Fischer proposed the "lock and key" model, in which the substrate fits the enzyme's active site exactly; in 1958 Daniel Koshland refined it with "induced fit", in which the enzyme changes shape as the substrate binds. In 1913 Leonor Michaelis and Maud Menten wrote the equation linking reaction rate to substrate concentration, still a cornerstone of biochemistry. In 1965 David Phillips's team used X-rays to solve the 3D structure of lysozyme, letting scientists watch an enzyme work at atomic scale. Enzymes are sensitive to temperature and pH and denature at high heat. In 1982 Thomas Cech discovered that RNA can also act as an enzyme (a ribozyme), supporting the "RNA world" hypothesis of life's origin.
Enzymes in the body and industry
Amylase in saliva, pepsin in the stomach and lipase from the pancreas break down food, and acetylcholinesterase destroys acetylcholine in an instant to end nerve signals. Missing one enzyme can cause disease: declining lactase in adulthood leads to lactose intolerance, and lacking the enzyme that breaks down phenylalanine causes phenylketonuria. Penicillin blocks bacterial cell-wall enzymes, and aspirin blocks enzymes that make inflammatory molecules. Industry uses enzymes in laundry detergents, rennet for cheese and high-fructose syrup; in 2018 Frances Arnold won the Nobel Prize in Chemistry for designing new enzymes by directed evolution. Most "enzyme supplements", however, are simply digested in the stomach like other proteins, and evidence for health benefits is weak. See a doctor if digestive problems persist.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Do enzyme supplements improve digestion or help weight loss?
- Enzymes eaten as food are mostly broken down by stomach acid and digestive enzymes, so they do not boost the body's own enzymes. Prescription digestive enzymes help only in conditions such as pancreatic insufficiency.
- Why is a very high fever dangerous?
- Human enzymes work best around body temperature, and too much heat unravels (denatures) their protein structure. Seek medical help if a high fever persists.
Sources reviewed: 2026-10-26
References
- Payen, A., & Persoz, J.-F. (1833). Mémoire sur la diastase, les principaux produits de ses réactions et leurs applications aux arts industriels. Annales de Chimie et de Physique, 53, 73–92.
- Kühne, W. (1877). Über das Verhalten verschiedener organisirter und sog. ungeformter Fermente. Verhandlungen des naturhistorisch-medicinischen Vereins zu Heidelberg, 1, 190–193.
- Fischer, E. (1894). Einfluss der Configuration auf die Wirkung der Enzyme. Berichte der deutschen chemischen Gesellschaft, 27(3), 2985–2993.
- Buchner, E. (1897). Alkoholische Gährung ohne Hefezellen. Berichte der deutschen chemischen Gesellschaft, 30(1), 117–124.
- Michaelis, L., & Menten, M. L. (1913). Die Kinetik der Invertinwirkung. Biochemische Zeitschrift, 49, 333–369.
- Sumner, J. B. (1926). The isolation and crystallization of the enzyme urease. Journal of Biological Chemistry, 69(2), 435–441.
- Koshland, D. E. (1958). Application of a theory of enzyme specificity to protein synthesis. PNAS, 44(2), 98–104.
- Blake, C. C. F., et al. (1965). Structure of hen egg-white lysozyme: A three-dimensional Fourier synthesis at 2 Å resolution. Nature, 206(4986), 757–761.
- Kruger, K., et al. (1982). Self-splicing RNA: Autoexcision and autocyclization of the ribosomal RNA intervening sequence of Tetrahymena. Cell, 31(1), 147–157.
- Arnold, F. H. (1998). Design by directed evolution. Accounts of Chemical Research, 31(3), 125–131.