Question

if you were to expose glucose to oxygen on your lab bench, why would you not expect to see it burn as described by the reaction in the figure below?
activation energy is required for the sugar and oxygen to reach their transition state.
the reaction is endergonic and requires an input of energy.

Explanation:

The reaction of glucose with oxygen is exergonic (releases energy), not endergonic. However, even exergonic reactions need activation energy to reach the transition state. Without sufficient activation energy (like heat from a spark in combustion), the reaction won't proceed spontaneously on the lab bench.

Answer:

Activation energy is required for the sugar and oxygen to reach their transition state.