Who proposed the lock and key hypothesis ?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the person who proposed the lock and key hypothesis related to enzyme action.

2. **Definition of Lock and Key Hypothesis**: The lock and key hypothesis is a theory that explains how enzymes interact with substrates. It suggests that the enzyme's active site (the "lock") is specifically shaped to fit a particular substrate (the "key").

3. **Historical Context**: This hypothesis was introduced to explain the specificity of enzymes in catalyzing biochemical reactions.

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