Differences between Respiracion-Aerobia-Anaerobia
Contents
Aerobic vs. Anaerobic Respiration
Cellular respiration is a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into adenosine triphosphate (ATP).[1] The primary difference between the two main types of cellular respiration, aerobic and anaerobic, is the use of oxygen.[2] Aerobic respiration requires oxygen as the final electron acceptor, while anaerobic respiration uses other molecules.[2]
Comparison Table
| Category | Aerobic Respiration | Anaerobic Respiration |
|---|---|---|
| Oxygen Requirement | Requires oxygen[3] | Does not require oxygen[3] |
| Primary Location | Cytoplasm (glycolysis) and mitochondria | Cytoplasm only |
| Reactants | Glucose and oxygen[4] | Glucose[5] |
| Products | Carbon dioxide, water, and ATP[4] | Lactic acid or ethanol, carbon dioxide, and ATP[2] |
| Energy Yield (ATP) | High (approx. 30–32 ATP per glucose molecule) | [1] Low (2 ATP per glucose molecule) |
| Stages Involved | Glycolysis, Pyruvate Oxidation, Krebs Cycle, and Oxidative Phosphorylation | Glycolysis and Fermentation |
| Organism Examples | Most animals and plants | Yeast, many bacteria, and animal muscle cells during intense exercise |
Aerobic Respiration
Aerobic respiration is a highly efficient process that completely breaks down glucose to produce a large amount of ATP. This process occurs in four main stages. It begins with glycolysis in the cytoplasm, where one molecule of glucose is split into two molecules of pyruvate. The pyruvate molecules then move into the mitochondrial matrix for pyruvate oxidation, converting them into acetyl-CoA. The third stage is the Krebs cycle (also known as the citric acid cycle), which also takes place in the mitochondrial matrix. In this cycle, acetyl-CoA is further broken down, producing ATP, electron carriers (NADH and FADH₂), and carbon dioxide as a waste product. The final stage, oxidative phosphorylation, occurs on the inner mitochondrial membrane and involves the electron transport chain, where the majority of ATP is produced. Oxygen acts as the final acceptor for electrons in this chain, combining with hydrogen to form water.
The overall chemical equation for aerobic respiration is: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Anaerobic Respiration
Anaerobic respiration occurs in the absence of oxygen. It starts with glycolysis, the same initial pathway as aerobic respiration, which takes place in the cytoplasm and produces a net of two ATP molecules. Because oxygen is not available to serve as the final electron acceptor, the Krebs cycle and oxidative phosphorylation do not occur. Instead, the cell undergoes fermentation to regenerate the NAD+ needed for glycolysis to continue.
There are two common types of fermentation:
- Lactic Acid Fermentation: In this process, pyruvate from glycolysis is converted directly into lactic acid. This occurs in certain bacteria, like those used to make yogurt, and in the muscle cells of animals during strenuous exercise when oxygen supply is limited. The chemical equation is: C₆H₁₂O₆ → 2C₃H₆O₃ + 2 ATP
- Alcoholic Fermentation: In this type, pyruvate is converted into ethanol and carbon dioxide. This process is carried out by organisms such as yeast and is used in baking and the production of alcoholic beverages. The chemical equation is: C₆H₁₂O₆ →[5] 2C₂H₅OH + 2CO₂ + 2 ATP
Anaerobic respiration is much less efficient than aerobic respiration, yielding only two ATP molecules per molecule of glucose because the glucose is only partially broken down.
References
- ↑ 1.0 1.1 "wikipedia.org". Retrieved February 02, 2026.
- ↑ 2.0 2.1 2.2 "study.com". Retrieved February 02, 2026.
- ↑ 3.0 3.1 "wikipedia.org". Retrieved February 02, 2026.
- ↑ 4.0 4.1 "geeksforgeeks.org". Retrieved February 02, 2026.
- ↑ 5.0 5.1 "study.com". Retrieved February 02, 2026.
