The respiration which takes place without oxygen is known as anaerobic respiration. The microorganisms like yeast break down glucose (food) into ethanol, carbon dioxide and releases energy.
It is a type of cellular respiration that takes place in the absence of oxygen to produce energy. Lower organisms such as bacteria and yeast use this type. In other organisms, it occurs during heavy activities. The chemical equation for anaerobic respiration is
Glucose(C6H12O6) → Alcohol 2(C2H5O H) + Carbon dioxide 2(CO2) + Energy (ATP )