Question

the diagram shows an enzyme molecule.

Explanation:

To solve this, we recall the lock - and - key model of enzyme - substrate interaction. The substrate must fit into the enzyme's active site. So we need to find the molecule (substrate) whose shape is complementary to the enzyme's active site. By visually comparing the shapes, the green - colored option (top - left) has a shape that can fit into the enzyme's active site.

Answer:

The green - colored option (the one in the top - left, with the wavy - like shape that complements the enzyme's active site).