1. Lactic acid: This is produced in lactic acid fermentation, which occurs in animals (including humans) and some bacteria. It is the reason for muscle fatigue and soreness after intense exercise.
2. Ethanol (alcohol): This is produced in alcoholic fermentation, which occurs in yeast and some bacteria. It is used in the production of alcoholic beverages and bread.
While these are the most common products, other substances can be formed in anaerobic respiration depending on the organism and the specific conditions. For example, some bacteria can produce butyric acid, propionic acid, or hydrogen sulfide.
