Anaerobic respiration occurs when there is not enough oxygen.
In humans a common situation is during exercise when the oxygen supply is
less than the demand from the cells. Therefore the cells have to use anaerobic
respiration to get the energy. However you do not get the same products.
Anaerobic respiration produces a substance called lactic acid.
GLUCOSE à LACTIC ACID + (energy)
Anaerobic respiration can also be used to make alcohol. This reaction occurs
in microorganisms such as bacteria and yeast, which use glucose to form
carbon dioxide and ethanol. This process is known as fermentation
GLUCOSE à ETHANOL + CARBON DIOXIDE