A good example would be the oxidation of glucose (a monosaccharide) in aerobic respiration.
Oxygen is used during the oxidation of glucose and water is produced.[2]
This equation is a summary of what actually happens in three series of biochemical reactions: glycolysis, the Krebs cycle, and oxidative phosphorylation.
https://en.wikipedia.org/wiki/Substrate_(chemistry): how does an enzyme convert a substrate to a product
https://en.wikipedia.org/wiki/Relative_growth_rate
https://en.wikipedia.org/wiki/Chemostat