Final answer:
Aerobic respiration requires oxygen and generates more ATP with carbon dioxide and water as byproducts, while anaerobic respiration operates without oxygen and produces less ATP with byproducts like lactic acid or ethanol.
Step-by-step explanation:
Aerobic vs. Anaerobic Respiration
When constructing molecular models of aerobic and anaerobic respiration, it is important to showcase the key differences and similarities in the processes. Aerobic respiration occurs in the presence of oxygen and involves a series of metabolic processes that convert biochemical energy from nutrients into ATP, releasing carbon dioxide and water as waste products. On the other hand, anaerobic respiration does not require oxygen and typically results in the production of less ATP alongside different waste products, such as lactic acid or ethanol, during fermentation.
In both aerobic and anaerobic respiration, the common process is glycolysis, where glucose is broken down into pyruvate. Glycolysis is considered to have evolved before other stages of cellular respiration because it is found in nearly all organisms and can function without oxygen, which suggests it was a critical step in early life forms that existed before atmospheric oxygen was abundant.
The main advantage of aerobic respiration is its high efficiency in generating ATP, while anaerobic respiration allows organisms to produce ATP in environments lacking oxygen. During intense, short bursts of activity, such as a 100-meter sprint, the muscles of an athlete like Tanya predominantly use anaerobic respiration to quickly generate energy. In contrast, Marissa’s muscles rely mainly on aerobic respiration for the prolonged effort required in a 5-kilometer run.