Now, in the absence of oxygen under anaerobic conditions, when we don't have plenty of oxygen present inside the cell, these Pyruvate molecules will undergo a process known as fermentation. Now, some cells in nature undergo alcohol fermentation and that produces ethanol from the Pyruvate. Other organisms, for instance, cells of our body undergo lactic acid fermentation and that transforms the Pyruvate into lactic acid or the conjugate base of lactic acid is lactate. So inside our body, when the cells of our body don't have enough oxygen, they will take the pyruvates and transform them into lactic acid molecules. Now, what happens if there is oxygen present in the cells of our body? Well, in the case of aerobic conditions, when we have oxygen present in the cell, the Pyruvate molecules will move into the mitochondria of the cell.