Which of the following is considered a model for enzyme action?

The Lock and Key model is considered a fundamental concept in understanding enzyme action because it illustrates how enzymes interact specifically with their substrates. In this model, the enzyme is compared to a lock, and the substrate is viewed as a key that fits perfectly into that lock. This specificity ensures that enzymes catalyze only particular reactions by binding to corresponding substrates, much like a key can only open a specific lock.

This model emphasizes the unique shape of both the enzyme and substrate, highlighting how the complementary structures allow for a precise fit. Once the substrate binds, the enzyme can facilitate the chemical reaction, converting substrates into products through its active site. This understanding forms a critical basis for biochemistry and molecular biology as it explains the high degree of selectivity of enzymes in biochemical pathways.