Who demonstrated the presence of enzymes and helped inaugurate biochemistry and metabolism study?

• A. Eduard Buchner
• B. Louis Pasteur
• C. Joseph Lister
• D. Linnaeus

Answer: (A)

Enzymes can drive biochemical reactions outside living cells, which makes metabolism approachable as a chemistry problem rather than something only happening inside organisms. Eduard Buchner demonstrated this with cell-free fermentation experiments: by crushing yeast and then heating the mixture to kill the cells, he showed the resulting extract could still ferment sugars to ethanol and carbon dioxide. This proved that enzymes in the yeast extract, not intact cells, carried out the reaction. This cell-free demonstration laid the groundwork for biochemistry and established metabolism as a field studied at the molecular level. Louis Pasteur showed fermentation involves living organisms and their metabolism, but he didn’t show that enzymes can function outside cells. Joseph Lister contributed to antiseptic techniques, and Linnaeus developed taxonomic classification; neither addressed enzymatic metabolism. Buchner’s work specifically identifies enzymes as the agents of fermentation and marks the birth of biochemistry.