How does aerobic respiration work

Anaerobic respiration Most organisms cannot respire without oxygen but some organisms and tissues can continue to respire if the oxygen runs out. This table compares aerobic and anaerobic respiration: Aerobic respiration Anaerobic respiration Oxygen Present Absent or in short supply.

Oxidation of glucose Complete Incomplete. All of the energy available from glucose is not released. Reactants of respiration Glucose and oxygen Glucose. Yeast - ethanol and carbon dioxide and ATP. Some plants - ethanol and carbon dioxide and ATP. Absent or in short supply. Glucose and oxygen. Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view.

It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs. How does Aerobic Respiration work during exercise? National Academy of Sports Medicine. Discovery Health. The reaction can proceed in either direction, but the reaction from left to right is inhibited by acidic conditions. Such lactic acid accumulation was once believed to cause muscle stiffness, fatigue, and soreness, although more recent research disputes this hypothesis.

Once the lactic acid has been removed from the muscle and circulated to the liver, it can be reconverted into pyruvic acid and further catabolized for energy.

Another familiar fermentation process is alcohol fermentation, which produces ethanol, an alcohol. The use of alcohol fermentation can be traced back in history for thousands of years. The chemical reactions of alcoholic fermentation are the following Note: CO 2 does not participate in the second reaction :. Alcohol Fermentation : Fermentation of grape juice into wine produces CO2 as a byproduct.

Fermentation tanks have valves so that the pressure inside the tanks created by the carbon dioxide produced can be released. The first reaction is catalyzed by pyruvate decarboxylase, a cytoplasmic enzyme, with a coenzyme of thiamine pyrophosphate TPP, derived from vitamin B 1 and also called thiamine.

A carboxyl group is removed from pyruvic acid, releasing carbon dioxide as a gas. The loss of carbon dioxide reduces the size of the molecule by one carbon, making acetaldehyde. The fermentation of pyruvic acid by yeast produces the ethanol found in alcoholic beverages.

Ethanol tolerance of yeast is variable, ranging from about 5 percent to 21 percent, depending on the yeast strain and environmental conditions.

Without these pathways, that step would not occur and no ATP would be harvested from the breakdown of glucose. Other fermentation methods also occur in bacteria. The aerobic respiration equation is as follows:. During aerobic respiration, there is an exchange of gases where oxygen is absorbed and carbon dioxide is released.

It can be found in the mitochondria of the eukaryotes and the cytoplasm of the prokaryotes. The end products of aerobic respiration are water, carbon dioxide, and energy. During aerobic respiration, a total of 38 ATPs are produced, some of which are lost during the process. Also, during aerobic respiration, complete oxidation of carbohydrates takes place.

Aerobic respiration is relatively slower than anaerobic respiration. Aerobic respiration occurs in most of the higher species including plants and animals. Cellular respiration in humans is an example. In anaerobic respiration, the process occurs in the absence of oxygen. Examples of an anaerobic respiration equation are the following:. During anaerobic respiration exchange of gases does not take place.

However, some organisms release some gases, such as sulfur and nitrogen gases. Anaerobic respiration can be found only in the cytoplasm of a cell. The end products of anaerobic respiration vary, such as gases, alcohols, acids, and energy. In fermentation, only 2 ATPs are produced. Also, there is incomplete oxidation of carbohydrates.

It occurs in simple prokaryotes, yeasts, and the muscle cells of humans during intense exercise. Anaerobic respiration is shorter than aerobic respiration. To summarize what has been described so far, here are the equations of various cellular respirations:.

All living organisms undergo cellular respiration. In certain types of bacteria and yeast, anaerobic respiration is preferred.

It gives them the advantage of surviving or thriving in an anoxic environment that would be lethal to aerobic organisms. Anaerobic respiration also has a very high speed. It produces ATP very rapidly. Aerobic respiration, on the other hand, produces ATP rather slowly. One of the most significant functions of fermentation is that it protects the cells from dying in the small amount of time between each breath and during intense activity when the red blood cells fail to provide adequate oxygen to the body cells due to under-oxygenation.

Fermentation takes over as this happens and releases a substance called lactic acid which keeps the cells of the body intact during the above-mentioned cycles of under-oxygenation. Although this quite useful for the time being, yet unfortunately, a build-up of lactic acid may cause discomfort in the muscles later. Lactic acid production in muscles.

During vigorous exercise, our muscles use oxygen to generate more ATP as compared to the supply. When this happens, the muscle cells undergo glycolysis faster than they can supply oxygen to the mitochondrial electron transport chain. As a result, anaerobic respiration and lactic acid fermentation occur within the cells and during extended activity, the built-up lactic acid will keep our muscles painful.

Alcoholic fermentation by yeasts. Fermentation is another category of anaerobic respiration that occurs in anaerobic organisms such as yeast. When carbohydrate-rich substances are bottled with yeasts to ensure a minimal oxygen level in the container, yeasts undergo the process of anaerobic respiration. As a process, fermentation occurs where the yeast converts sugars into ethyl alcohol.