Biology · Enzymes

Koshlan proposed the "Induced Fit Model" of enzyme action in the year 1959.

This is the correct answer.

Daniel E. Koshland Jr. proposed the Induced Fit Model of enzyme action in 1959. This model refined the older “lock and key” idea, suggesting that the enzyme’s active site changes shape slightly to fit the substrate more precisely once it binds — enhancing catalytic efficiency.

Incorrect. No such enzyme model was introduced in 1952. During this time, the lock and key model by Emil Fischer (1894) was still the dominant explanation, not Koshland’s induced fit model.

Incorrect. Although enzymology was an active field in the 1950s, the induced fit concept was not introduced until 1959. No significant enzyme theory publication by Koshland appeared in 1954.

Incorrect. This predates Koshland’s formal proposal of the induced fit model. In the mid-1950s, enzyme-substrate interaction was still explained mainly by the lock and key theory.

Incorrect. This is too early; Koshland’s model had not been developed yet. The induced fit model was only formulated in 1959 based on emerging biochemical evidence and protein flexibility studies.