Fireflies emit light. The production of light by an organism is called bioluminescence. To generate visible light, cells in a firefly's tail produce
thousands of luciferase enzymes. Luciferase binds to a chemical called
luciferin. Once bound, the luciferase enzyme speeds up a chemical reaction
that combines an oxygen molecule and luciferin to produce oxyluciferin. This
reaction requires energy and releases light. Which of the following best
describes how the luciferase enzyme speeds up the chemical reaction?