Final answer:
Glucose is split into two molecules of pyruvate during glycolysis. This process also generates ATP and NADH. Pyruvate can then proceed to aerobic or anaerobic pathways depending on the availability of oxygen.
Step-by-step explanation:
The glucose that enters the glycolysis pathway is split into two molecules of pyruvate. Glycolysis is a process where one glucose molecule (C6H12O6) is broken down into two three-carbon molecules of pyruvate (C3H4O3) in a series of enzymatic reactions. This metabolic pathway occurs in the cytosol of cells and represents the first major step in cellular respiration. The process consists of multiple steps that not only generate pyruvate but also produce energy in the form of ATP and reducing power as NADH. Specifically, four molecules of ATP and two molecules of NADH are produced per molecule of glucose that enters glycolysis.
Moreover, the pyruvate molecules generated can either enter anaerobic pathways, such as lactic acid fermentation or alcoholic fermentation, or they can be further metabolized aerobically in the mitochondria to produce additional ATP. If oxygen is present, pyruvate is typically transported into the mitochondrial matrix where it is converted into acetyl-CoA by pyruvate dehydrogenase, to enter the citric acid cycle (also known as the Krebs cycle).