key-lock hypothesis
Quick Summary
The key-lock hypothesis, proposed by Emil Fischer in 1899, describes enzyme specificity by suggesting that the active site of an enzyme has a fixed shape that precisely fits a specific substrate, much like a key fits a lock. However, the induced-fit theory, a more current model, posits that while a substrate must fit the active site, its binding also causes a change in the enzyme's shape to enhance or inhibit activity. This is often compared to a hand fitting into a glove. This flexibility allows enzymes to regulate their activity through interactions with activators and inhibitors.12
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proteinThe role of the active site…and enzyme, called the “key–lock” hypothesis, was proposed by German chemist Emil Fischer in 1899 and explains one of the most important features of enzymes, their specificity. In most of the enzymes studied thus far, a cleft, or indentation, into which the substrate fits is found at the active…
Read More…and enzyme, called the “key–lock” hypothesis, was proposed by German chemist Emil Fischer in 1899 and explains one of the most important features of enzymes, their specificity. In most of the enzymes studied thus far, a cleft, or indentation, into which the substrate fits is found at the active…
Read More- proteinThe induced-fit theory
The key–lock hypothesis (see above The nature of enzyme-catalyzed reactions) does not fully account for enzymatic action; i.e., certain properties of enzymes cannot be accounted for by the simple relationship between enzyme and substrate proposed by the key–lock hypothesis. A theory called the induced-fit theory retains…
Read MoreThe key–lock hypothesis (see above The nature of enzyme-catalyzed reactions) does not fully account for enzymatic action; i.e., certain properties of enzymes cannot be accounted for by the simple relationship between enzyme and substrate proposed by the key–lock hypothesis. A theory called the induced-fit theory retains…
Read More