In the lock-and-key model of enzyme function shown in Figure 2.2 what is happening in step 1?

In step 1 of the lock-and-key model of enzyme function, the substrate (the key) fits into the enzyme's active site (the lock) with precise specificity. This interaction forms an enzyme-substrate complex, allowing the enzyme to stabilize the transition state and facilitate the chemical reaction. The model emphasizes the complementary shapes of the enzyme and substrate, illustrating how enzymes are selective in their action on specific substrates.