Profile
Settings
Refer your friends
Sign out
Cellular respiration is a process that all living organisms go through. It is described as a set of metabolic processes in which an organism’s living cells obtain energy (in the form of ATP) by inhaling oxygen and exhaling carbon dioxide produced by the oxidation of complex organic molecules. The process occurs inside different types of cells, where biochemical energy is extracted from an organic substance and stored in an energy-carrying molecule for use in the cell’s energy-demanding functions.
The primary purpose of cellular respiration is to produce metabolic energy in both the cytosol and mitochondria of cells. Both eukaryotic and prokaryotic organisms require cellular respiration because this biochemical energy is used to power various metabolic processes such as motility, biosynthesis, and molecule transport across membranes.
Types of Cellular Respiration
Depending on the environmental conditions, many species have altered their biological processes to carry out cellular respiration operations either aerobically or anaerobically. The reactions involved in cellular respiration are incredibly complicated, including a complex collection of metabolic reactions within the organism’s cells. Cellular respiration includes the processes of glycolysis, pyruvate oxidation, the citric acid or Krebs cycle and oxidative phosphorylation.
The two basic types of cellular respiration are aerobic and anaerobic respiration.
Aerobic respiration occurs in all plants and higher animals, including humans, mammals, and birds. Anaerobic respiration is a type of cellular respiration that occurs in all lower organisms, including bacteria and yeast, without oxygen.
1. Aerobic Respiration
Aerobic respiration is a type of cellular respiration that breaks down complex molecules to produce energy in the form of ATP high-energy molecules in the presence of oxygen. Most eukaryotes and certain prokaryotes use cellular respiration to be the most efficient. Aerobic respiration causes the complete oxidation of carbohydrates to provide the most energy.
The oxygen molecule serves as the final electron acceptor in aerobic respiration, resulting in efficient ATP synthesis. The exchange of oxygen and carbon dioxide gas occurs over a significantly extended period. Because the double bond in the oxygen molecule aids the ATP synthesis process, aerobic respiration is more efficient than anaerobic respiration.
After the phosphate group is added to ADP molecules, the end products of aerobic respiration include carbon dioxide and water, and ATP. In addition, during aerobic respiration, which produces ATP via the electron transport chain, other energy-rich molecules such as NADH and FADH2 are created. At the end of aerobic respiration, 36 ATPs should be generated; however, some energy is wasted due to membrane leakage.
2. Anaerobic Respiration
Anaerobic respiration is a kind of cellular respiration in which oxygen or pyruvate derivatives are not used as a high-energy electron acceptor. In the absence of oxygen, it takes place in prokaryotic cells, resulting in the production of an acid or alcohol as a byproduct. In anaerobic respiration, other molecules or ions, such as sulphate or nitrate, take the place of oxygen as the final electron acceptor. Anaerobic respiration byproducts vary depending on the type of anaerobic respiration used.
Prokaryotes that live in low-oxygen conditions, such as deep-sea surfaces, are more likely to use anaerobic respiration. Because the types of coenzymes used in cellular respiration that are essential for anaerobic respiration are found in the cell’s cytoplasm, the process occurs there.
Many types of anaerobic respiration or fermentation exist, depending on the electron acceptors and byproducts. Because the final electron acceptor has a lower reduction potential than oxygen molecules, anaerobic respiration is less effective than aerobic respiration. On the other hand, Anaerobic respiration is critical for sulphur, carbon, and nitrogen biogeochemical cycles.
Important distinctions (Aerobic Respiration vs Anaerobic Respiration)
Fundamentals for comparison | Aerobic respiration | Anaerobic respiration |
Definition | Aerobic respiration is a set of metabolic processes that occur when there is oxygen present in a cell and transforms chemical energy into ATPs. | Anaerobic respiration is cellular respiration that does not use oxygen or pyruvate derivatives as a high-energy electron acceptor. |
Overall equation | The entire aerobic respiration equation is: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy | Anaerobic respiration’s overall equation is: C6H12O6 → C2H5OH + CO2 + energy |
Presence of Oxygen | When there is an abundance of oxygen, aerobic respiration takes place. | When there is a shortage of oxygen in the environment, anaerobic respiration occurs. |
Conversation of gases | Gas exchange occurs when oxygen is taken in, and carbon dioxide is released throughout aerobic respiration. | The exchange of gases is not part of anaerobic respiration. However, some species, such as bacteria, produce gases like sulphur and nitrogen. |
Location | After glycolysis, eukaryotes’ mitochondria and prokaryotes’ cytoplasm undergo aerobic respiration. | Anaerobic respiration occurs only in the cytoplasm of a cell. |
Final products | During aerobic respiration, 38 ATPs are created, with some of them being misplaced in the process. | Only two ATPs are created for the duration of anaerobic respiration. |
Reactants | For aerobic respiration to take place, carbohydrates and oxygen are required. | Other electron acceptors such as sulphur and nitrogen are necessary along with the carbohydrates. |
Oxidation | During aerobic respiration, carbohydrates are completely oxidised. | For the period of anaerobic respiration, carbohydrates are partially oxidised. |
Nature of the process | Aerobic respiration lasts longer than anaerobic respiration. | Anaerobic respiration lasts a shorter time than aerobic respiration. |
Occurs in | Aerobic respiration is used by most higher species, including animals and plants. | Anaerobic respiration has always been present in prokaryotes. During forceful movements in humans, anaerobic respiration occurs in muscle cells. |
Conclusion
Cellular respiration is a critical activity that gives usable energy to organisms. It is a biological reaction within animal cells and a metabolic process in all species. During this process, energy (ATP-Adenosine triphosphate) is produced by the breakdown of glucose, which is subsequently used by cells to perform numerous functions. Both eukaryotic and prokaryotic cells require cellular respiration because this biochemical energy is used to power various metabolic functions such as motility, biosynthesis, and molecule transport across membranes. Cellular respiration is carried out by all living entities, from single-celled organisms to dominant multicellular animals.
