The Difference Between Aerobic and Anaerobic Glucose Breakdown
In a nutshell, aerobic respiration uses oxygen to break down glucose. On the other hand, anaerobic respiration uses a toxic form of oxygen.
These two pathways’ differences are significant for understanding the body’s functions. This article discusses both pathways and their respective benefits and drawbacks.
Aerobic metabolism, or aerobic respiration, is the energy production of living organisms. This process requires oxygen and produces ATP molecules. On the other hand, Anaerobic metabolism is the energy production in cells that do not require oxygen, such as those found in muscles and some brain tissues. In anaerobic respiration, glycolysis breaks down glucose molecules to pyruvate inside cells.
Then pyruvate is converted into acetyl coenzyme A (acetyl-CoA), which leads to mitochondrial beta-oxidation of fatty acids for long-term energy storage within cells. About 90% of the glucose inside cells is converted to acetyl-CoA for the production of ATP. The remaining 10% is converted to lactic acid by fermentation, which is common in animals. Anaerobic respiration has a relatively fast pace but produces low yields of ATP.
The most common types of aerobic metabolism are glycolysis, the citric acid cycle (also known as the Krebs cycle), oxidative phosphorylation, and photosynthesis. After glycolysis, pyruvate is formed from glucose as an intermediate step in cellular respiration. Pyruvate can then be converted into acetyl-CoA, which is further converted into ATP in the citric acid cycle. The citric acid cycle takes place in mitochondria and produces NADH as energy.
There are two significant ATP yields from aerobic respiration: a fast, wasteful ATP yield (chemical phosphorylation) and a slow non-fossil source yield—the fast yield of ATP results from the chemical phosphorylation portion of respiration that produces adenosine triphosphate. The non-fossil fuel source for this rapid ATP yield is formed by breaking down glucose without oxygen metabolism. The slow non-fossil source ATP yield comes from the glycolysis of carbohydrates and fats, transforming glucose into acetyl-CoA. The slow non-fossil fuel source does not provide an immediate source of ATP, but it is stored in cells for future use.
Aerobic respiration produces about 36 molecules of ATP per glucose molecule. By contrast, anaerobic respiration produces only two molecules of ATP for every molecule of glucose without oxygen. Anaerobic respiration is found in the muscles and the brain. This is due to these cells not having mitochondria. Mitochondria are tiny organelles that produce energy during aerobic respiration.
Fermentation is an Aerobic Pathway
Fermentation is the aerobic pathway for glucose breakdown in organisms. This process requires several enzymatic steps, ranging from glycolysis to pyruvate formation. Evolutionary speculation cannot explain the precise mechanisms behind this multistep process. These enzymes have intricate regulatory mechanisms that cannot be explained by simple genetics alone.
Fermentation is an anaerobic pathway that breaks down sugar molecules into substances needed for creating chemical energy, usually in the form of ATP, which fuels various biological processes. It is more complex than aerobic respiration because it uses no oxygen.
The first two enzymes involved in glycolysis generate two ATPs, which are then converted into ADP. The following two enzymes in this process generate four ATPs each. The final phase of glycolysis also produces pyruvate, a product of the energy-payoff phase. Pyruvate is then used to regenerate NAD+.
Fermentation is a common pathway for the breakdown of glucose. It uses enzymes to break down glucose and create byproducts such as alcohol. Alcoholic fermentation is a form of glycolysis and uses 11 enzymes to convert glucose to lactic acid. Alcoholic fermentation also involves lactic acid, formed when the cells lack oxygen.
Fermentation can also be used to produce energy. Some organisms, like yeasts, perform anaerobic respiration, which uses a different molecule for electron acceptors instead of oxygen. However, this process is not used by humans. Therefore, it is essential to understand how fermentation works and how it differs from anaerobic respiration.
In the aerobic state, glucose is broken down into pyruvate, which enters the citric acid cycle, undergoes oxidative phosphorylation, and is converted to lactate. Both steps result in the production of two ATP molecules. These two reactions are essential for the breakdown of carbohydrates and energy in the body.
Fermentation also occurs in the muscle cells during vigorous physical activity. When the cells release lactate, it is carried by the blood to the liver, where an enzyme converts it back to pyruvate. This is known as the Cori cycle. Fermentation can occur either in the aerobic or anaerobic direction, and the chemical equation changes depending on the reactants and products.
Fermentation produces carbon dioxide as a waste product. Fermentation is also used in dairy to make yogurt and cheese. Fermentation also happens in alcohol fermentation, making wine and liquor. Besides fermenting carbohydrates, fermentation can also produce acetic acid and lactic acid.
Fermentation requires complex cofactors for glucose breakdown, including dehydrogenase enzyme and nicotinamide adenine dinucleotide (NAD+). The reduced cofactor (NAD+) must be continually replenished. In alcoholic fermentation, alcohol dehydrogenase is also required.
Aerobic Respiration uses Oxygen
Aerobic respiration is the process in which cells use oxygen and glucose to break down food molecules. This process occurs inside the mitochondria and cytoplasm of cells. For example, it breaks glucose down into carbon dioxide and ethyl alcohol, used as energy. Higher organisms perform this process, while lower organisms use anaerobic respiration. In aerobic respiration, glucose is broken down into energy and stored in ATP molecules.
The acetyl group is the first component of aerobic respiration, which is made of two carbon atoms. These two atoms represent four of the six carbons in the glucose molecule. Two carbon dioxide molecules are released on each cycle turn, but they may contain less recently added carbon atoms. Eventually, all six carbon atoms of a glucose molecule are converted to carbon dioxide. The last portion of aerobic respiration is the electron transport chain, which involves four complexes of proteins and accessory electron carriers.
Aerobic respiration began when oxygen levels were high enough to allow organisms to grow larger and more rapidly. The advantage of oxidation is that it provides a higher yield of ATP, which can be used in a broader range of chemical reactions. Furthermore, oxidation can occur with a much more comprehensive range of reductive substances.
Aerobic respiration occurs in human muscles, yeast, and many other eukaryotes. It is the process of moving oxygen from one place to another, and it releases carbon dioxide in the process. Most organisms use both forms of respiration for different purposes. However, anaerobic respiration is considered less efficient, as it does not use oxygen as an electron acceptor. It is the process used in plants and animals for energy production.
Aerobic respiration is 19 times more efficient than anaerobic respiration and is more efficient for prolonged effort. It also provides more energy than anaerobic respiration. This is because it releases energy in the form of ATP, while anaerobic processes leave most of the source of ATP in waste products.
The process of cellular respiration is an essential process for all living things. This process occurs in two types of cells, autotrophs, and heterotrophs. The first process stage, glycolysis, breaks down glucose in the cell cytoplasm. There, glucose is broken down through chemical reactions and forms pyruvate, which enters the mitochondria. It then undergoes a series of chemical reactions with oxygen to produce water and carbon dioxide.
Anaerobic Respiration uses a Toxic form of Oxygen
Anaerobic respiration is cellular respiration, whereby an organism uses a toxic form of oxygen to break down glucose. It allows organisms to harvest more energy from their food and use it for growth and reproduction. However, it also produces different waste products.
Anaerobic respiration occurs when nerve cells use glucose for energy instead of fatty acids. The brain contains many nerve cells, which consume approximately two-thirds of the blood glucose. The liver is the body’s largest organ, and it converts glucose into glycogen, a starch-like substance produced by animals. The remaining glucose is taken up by muscle cells, which use some of it to produce energy called ATP.
Anaerobic respiration uses a highly toxic form of oxygen to break down glucose and produce energy. This process also requires an electron acceptor. Several bacteria and other organisms can perform both types of respiration. Although human cells depend on aerobic respiration, anaerobic respiration is crucial in many biological processes. For example, anaerobic respiration is essential for cells when oxygen levels are low.
Anaerobic respiration can also lead to lactic acidosis, a condition in which the body cannot use the oxygen in the air. Cancer cells are particularly adept at glycolysis. The process allows these cells to produce much ATP without needing oxygen, giving them an advantage over normal cells.
Anaerobic respiration also involves fermentation, a pathway that does not require oxygen. However, fermentation has one or two different reactions at the end of the process. The different reactions regenerate NAD+ from NADH, allowing it to drop electrons to organic molecules.
Anaerobic respiration is similar to aerobic respiration in that electrons are extracted from fuel molecules and passed through an electron transport chain. These electrons are then used to drive ATP synthesis in the cells. Some bacteria and archaea also carry out anaerobic cellular respiration.
As a result, oxygen can cause damage to organisms. Single electron transfer from one oxygen atom to another generates a toxic form of oxygen called superoxide radical, which attacks several vital biomolecules. This is a significant threat to life, so organisms develop specific enzymes and anti-oxidants to protect themselves from this gas.