COACHES
Section: Medicine and Sports Sciences
The mole in sports medicine and exercise physiology
The intense specialization in sports medicine has led to a situation in which physicians, coaches, and athletes are often unfamiliar with the scientific nomenclature used. In such nomenclature, the mole is used to specify multiple values of high biochemical relevance. A clear understanding of the meaning of the mole will allow the reader to correctly interpret the metabolic activities related to the performance of athletes.
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The mole represent a quantity that is counted and therefore responds to numerical values. At the scale of atoms and molecules, one mole of atoms contains 6.02 x 10²³ atoms, while one mole of molecules contains 6.02 x 10²³ molecules. The mole represents a very high number of items, to be exact 6.02 x 10²³ of such items.
In the many studies and analyzes that are carried out in sports medicine, and especially in biochemistry and physiology, we doctors use the mole to designate the amount of a certain substance that contains a standard number of particles. Such particles can be atoms, molecules, or ions, and there will always be the same number of items in one mole. Without knowing this numerical unit perfectly, it is very difficult, if not impossible, to interpret any study and / or analysis regarding the state of fitness and / or health of athletes.
In 1811 the Italian physicist Amadeo Avogadro (1776–1856) suggested that a given volume of any gas at the same temperature and pressure contained the same number of molecules. This concept eventually became Avogadro’s Law or Constant, which makes it possible to determine the comparative weights of different atoms and molecules by measuring the density of the gases in question.
Avogadro’s Law or Constant, also known as Avogadro’s Number, with a symbol (N or NA), corresponds to the number of particles found in the amount of substance represented by one mole. Thus, one mole of a given substance is equivalent to 6.02214129 × mol⁻¹ elemental units, where one mole of an element is equivalent to 6.02 x 10²³ atoms of such an element.
It is clear that the reader will never weigh the mass of an atom or molecule on a scale since both are too small, even for the most sensitive scales. Despite this, and in the laboratory, we usually work with samples that can be weighed on a scale in grams. What is known as the molar mass or mass of 1 mole of a given substance is equivalent to the atomic or molecular mass depending on whether one mole of atoms or molecules has been considered, expressed in grams.
For example, the atomic weight of carbon is 12, and its molar mass is 12 grams; therefore in a molar mass (12 grams) of carbon, there are 6.02 x 10²³ carbon atoms. In the same way, the weight of the carbon dioxide (CO2) formula is 44 grams and contains 6.02 x 10²³ carbon dioxide molecules – that is, one mole. The molar mass of an element or compound is one of the most practical and useful numerical values in science.
Since 1971, and according to the Universal System of Units (SI), the mole is specifically defined as: “The amount of substance in a system containing as many elemental units as there are atoms in 0.012 kg of carbon-12.” If the mole is used, the elemental units must be specified and may be atoms, molecules, ions, electrons, or other particles or groups determined by those particles. The term “Mole” It first appeared in 1902, used to express the molecular weight of a substance.
We can get a conceptual idea of the volume of particles contained in a mole of substance taking as reference a mass of marbles or standard glass balls of 16 millimeters in diameter each. If these were scattered over the entire surface of the Australian continent (8.6 million square kilometers) they would form a layer almost 80 km thick.
In summary: 1.- the Constant or Avogadro’s Number corresponds to the number of items in 1 mole, this being equal to 6.02 x 10²³; 2.- 1 mol corresponds to a group of atoms, molecules, or formula units that contains 6.02 x 10²³ of such items; and 3.- a molar mass is the mass of a mole of a certain element or compound, being equivalent to the weight of the formula expressed in grams.
Despite its central importance in sports medicine, and exercise physiology and biochemistry, the mole (mole) as a unit turns out to be inconveniently large. For this reason, and for practical purposes, it is more convenient to use the millimole (mmol), which is a unit a thousand times smaller than the mole.
Guillermo Laich
Medical director of the Las Rozas Medical Center. Specialist in Plastic, Reconstructive and Aesthetic Surgery (MIR). Professor of Medical and Surgical Pathology.
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