Scientists commonly compare cell respiration to a wood fire ignited by a match. What exactly is the "match" equivalent within a body that sparks the burn of oxygen and glucose in cell respiration?

by Jeff Jensen

Regarding cell respiration what exactly is the spark referred to in the analogy below that I found online? In that analogy I understand how a battery creates a spark to start a car and how the spark of a match creates a wood fire. What similar mechanism within the body causes the spark of cell respiration? Thank you.

Analogy found on the Internet:
"Paradoxically, we need ATP to create ATP. You have to provide that initial spark of energy to start the process. For example, even though your car runs on gas, you need a battery to provide that initial power to start it up. Another example is if you gather firewood, you need a spark from a match to start the fire."