aerobic respiration

Biologist

2022

We explain what aerobic respiration is, how it is carried out and examples. In addition, its different stages and anaerobic respiration.

Aerobic respiration takes place within the cells of living things.

What is aerobic respiration?

It is known as aerobic respiration or aerobic respiration to a series of metabolic reactions that take place within thecells of the living beings, through which you get Energy chemistry from the decomposition of molecules organic (cellular respiration).

It is a complex process of obtaining Energy, which consumes glucose (C6H12O6) as fuel and oxygen as final receptor for electrons (oxidant) in reaction with pyruvic acid (C3H4O3). It is obtained like thiscarbon dioxide (CO2), water (H2O) and numerous amounts of adenosine triphosphate (ATP), the molecule of biochemical energy par excellence.

This process is typical of eukaryotes and certain forms of bacterium, and occurs according to the following formula:C6H12OR6 + 6O2 → 6CO2 + 6H2O + ATP.

Examples of aerobic respiration

Birds use their lungs to obtain oxygen from the air.

Some examples of aerobic respiration are:

  • The metabolism of the Humans, reptiles, birds andmammals entirely, they use their lungs to get oxygen from the air.
  • The metabolism of fish and other aquatic beings, which have gills to obtain oxygen from the Water.
  • The metabolism of insects, which incorporate oxygen from the air through a series of windpipes throughout your body. Another case is worms and worms, which do the same for the skin (cutaneous respiration).

Stages of aerobic respiration

Aerobic respiration is a complex process that involves a series of stages in a prolonged chemical reaction. These stages are:

  • Glycolysis. The initial step of aerobic respiration occurs in the cytoplasm of the cell and is the oxidation of glucose (and glycerol from triglycerides, if any). This process breaks the bonds of each molecule of this sugar and obtains in exchange two molecules of pyruvic acid, along with two molecules of ATP.
  • Oxidative decarboxylation of pyruvic acid. Pyruvic acid molecules enter the cytoplasm into the matrix of mitochondria (energetic organelles of the cell), where they are processed by a complex ofenzymes (pyruvate dehydrogenase) that remove a carbon atom (decarboxylation), released as CO2, and then two hydrogen atoms (dehydrogenation). As a result, acetyl radicals (-CO-CH3) are obtained with which the next phase begins.
  • Krebs cycle. The last phase of respiration occurs in a metabolic cycle in the mitochondrial matrix, known as the Krebs Cycle. This begins with the acetyl from the previous phase, subjected to oxidation to produce two molecules of CO2 and energy in the form of Guanosine triphosphate (GTP) and other usable reducing molecules.

Then a chain of chemical reactions that reoxidize the enzymatic components reduced in the previous phase, making them available for a new use, and obtaining new ATP in the process.

The latter occurs already in the inner membrane of the mitochondria. The electrons and protons released in the process are taken in by oxygen which is then reduced to water.

Anaerobic respiration

Anaerobic respiration is distinguished from aerobic respiration by the presence of oxygen.

Anaerobic or anaerobic respiration differs from aerobic in one thing: the presence of oxygen. This type of cellular respiration consists of the oxidoreduction of monosaccharide sugars, using an element other than oxygen for oxidation: derivatives of nitrogen (nitrates), sulfur (sulfates and sulfides), carbon dioxide, ions iron or manganese, selenium (selenate), arsenic (arsenate), among others. These molecules are less effective and less energy is generated than using oxygen.

Anaerobic respiration is different from fermentation, and produces various substances as by-products, depending on the element used as an electron acceptor. This metabolic mechanism is typical of certain bacteria and microorganisms prokaryotes that inhabit environments low on oxygen.

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