What is a mechanism of a reaction?

A mechanism is a stepwise process that converts reactants to products. As we have seen a reaction may occur via a one-step mechanism, or by a two-step mechanism.

2G + B --> G2B

For this reaction it is less likely that the reaction would occur in a single step.

As we saw in the movie the reaction required two steps.

Step 1: G + G --> G2 (slow)

Step 2: G2 + B --> G2B (fast)