Final answer:
Anaerobic respiration produces fewer ATP molecules because it is limited to glycolysis with a net gain of two ATP, whereas aerobic respiration includes glycolysis, the citric acid cycle, and oxidative phosphorylation, yielding about 36-38 ATP per glucose molecule.
Step-by-step explanation:
Fewe ATP molecules are created during anaerobic respiration than aerobic respiration because in anaerobic respiration, the process is limited to glycolysis alone, which yields a net of only two ATP molecules. In the absence of oxygen, the electron transport chain cannot function, and so the high-energy electrons from NADH and FADH2 cannot be used to generate further ATP. Contrastingly, aerobic respiration uses the full breakdown of glucose through glycolysis, the citric acid cycle, and oxidative phosphorylation, producing approximately 36-38 ATP molecules from a single glucose molecule, due to the efficiency of the electron transport chain and oxidative phosphorylation.