Difference Between Aerobic and Anaerobic Metabolism

Aerobic vs Anaerobic Metabolism

Cell metabolism is the process of converting the carbohydrates, fats, and proteins into energy needed by cells. During the cell metabolism pathways, energy is stored in high-energy phosphate bonds of adenosine triphosphate molecules (ATP), which serves as the energy currency of cells. Depending on the oxygen demand during the production of ATP, there are two major types of metabolism present in the cell; namely, aerobic and anaerobic. Out of the three basic metabolic pathways, only glycolysis is considered as an anaerobic metabolism, whereas the rest including citric acid cycle (Krebs cycle) and electron transport chain are considered as aerobic metabolisms.

Aerobic Metabolism

Aerobic metabolism occurs when the oxygen is present. It occurs in the cell’s mitochondria and responsible for the supply of 90% of the body’s energy requirement. During aerobic metabolism, all the basic substrate including carbohydrates, fat, and protein are broken down and are combined with molecular oxygen to produce energy while releasing the carbon dioxide and water as end products. In general, oxidative metabolism produces nearly 150 to 300 mL of water in a 24 hour period of time. There are two pathways involved in aerobic metabolism; citric acid cycle; which occurs in the matrix of mitochondria, and electron transport chain; which occurs in the electron transport system located in the inner mitochondrial membrane.

Anaerobic Metabolism

Anaerobic metabolism does not require oxygen for the production of ATP. It occurs through the glycolysis, the process by which energy is liberated from glucose. Anaerobic metabolism’s efficiency is low, and produced low number of ATP when compared to aerobic metabolism. Glycolysis occurs in the cytoplasm and does not require any organelle. Therefore, it is an important process of which the organisms lack mitochondria such as prokaryotes. The end product of aerobic metabolism is lactic acid, which may be relatively harmful to the body.

Aerobic vs Anaerobic Metabolism

• Aerobic metabolism requires oxygen, whereas anaerobic metabolism does not.

• Anaerobic metabolism cannot continue indefinitely. In contrast, aerobic metabolism can continue forever, only under theoretical conditions.

• Carbohydrate, fat, and proteins are used as sources of aerobic metabolism while only carbohydrate is involved for anaerobic metabolism.

• Aerobic metabolism involves low to moderate intensity activities, whereas anaerobic metabolism involves only high intensity activities.

• Anaerobic metabolism takes place in the cytoplasm of cells while aerobic metabolism occurs in mitochondria.

• Aerobic metabolism produces more energy than anaerobic metabolism if the same amount of the same substrate.

• Glycolysis is an anaerobic metabolic pathway, whereas citric acid cycle and electron transport chain are aerobic metabolic pathways.

• Aerobic metabolisms contribute more (around 90%) for the supply of energy while anaerobic metabolism contributes less.

• End product of anaerobic metabolism is lactic acid while that of aerobic metabolism is carbon dioxide and water.

Image Source: Courtesy of http://webanatomy.net/anatomy/aerobic.jpg