Question

Give a scientific reason.

Oxygen is necessary for complete oxidation of glucose.

Answer 1

1. Glucose can be oxidised in two pathways, i.e. aerobic and anaerobic respiration. 
2. A molecule of glucose is completely oxidised in aerobic respiration (i.e., in the presence of oxygen) to form CO₂, H₂O, and energy (38 ATP). Three steps, namely glycolysis, the Krebs cycle, and the electron transfer chain.
3. However, in anaerobic respiration (i.e., in the absence of oxygen), glucose is incompletely oxidised. Glycolysis and fermentation result in the formation of organic acids or alcohols, with less energy produced.

Hence, oxygen is necessary for the complete oxidation of glucose.