Availability of energy | health-care-&-fitness

 

Availability of energy | health-care-&-fitness

Energy availability or supply of energy

 is the production, transport and breakdown of energy stores with the reorganization of ATP in human or animal muscle cells. This process of supply causes the muscles to work. There are many energy stores in the body for muscle performance, which are: creatine phosphate, carbohydrates, and fats or proteins. This is done by anaerobic (with oxygen) and anaerobic (with lactacid) (with or without lactate lactate) (lactate is lactic acid). As far as aerobic metabolism is concerned, it is carried by oxygen, and it is present in muscle cells, the mitochondria. As far as metabolism without oxygen is concerned, it is in the cytoplasm of the cell, not inside the mitochondria. When the latter work is completed and is accompanied by an increasing production of lactate (an intermediate phase produces a lactic acid in which there is no complete oxidation of oxygen), we call it "lactazed" ۔ Things outside of this are called "alactase" metabolism

Introduction

In order for a muscle to contract, it needs energy. This energy is produced by a chemical reaction that produces energy. During this process, electrical energy is converted into kinetic energy. Thus, the body needs a lot of energy to be able to move. The energy that muscles need to contract comes from the water storage in the ATP (cell battery) in the insulin diphosphate (ADP) and phosphate (PE). The ATP molecules provide muscle energy. But ATP reserves are very limited, so it is important for muscles to regenerate ATP during movement or during athletic training, so that the muscles can keep moving. The energy needed to restore adenosine triphosphate comes through the oxidation phase of foods such as sugars (carbohydrates), fats, or more precisely, fatty acids or proteins (amino acids).

There are various mechanisms along the way. A muscle has an anaerobic supply of energy (ie without oxygen) but then forms lactates; A process that does not use air (oxygen) to supply energy is called an anaerobic process. Another way to increase muscle energy is to burn the body's carbohydrates (glycogen) with oxygen. There is also a way to supply the muscles with energy by eating the fat stored in the body, and this process is done efficiently even in the presence of oxygen and this process is called aerobic process.

From history

The ATP was discovered in 1931 by chemist Carl Lohmann. Thus he also discovered that creatine phosphate is not a direct source of energy for muscles to perform their movements, as ATP acts as an enzyme partner, as a regulatory parameter in metabolism, and As an energy carrier, a more important role has been given. This provides energy directly to the muscle cells.

After discovering large amounts of ATP storage, and recognizing it as a direct source of muscle cell contraction and function, Lehman continued his efforts by explaining the chemical reaction involved. , Which is as follows:

Cretinophosphate + ADP; Cretan + ATP

(ATP + H₂O → ADP + P + Energie)

That is, when ATP energizes the myosin molecule in the muscle, it is converted to adenosine diphosphate (ADP) with the release of the phosphate atom. But in order for muscle function to continue, it is necessary to restore the structure of ATP, and this is done by interacting with the ADP, creatine phosphate and giving the phosphate atom, then re-ATP. Is formed (first equation). When ATP interacts with a water molecule, it produces energy and converts it into ADP, and the phosphate atom is released: the resulting energy signals the movement of the mousein molecule in the muscle. she does.

If it is a cycle: ATP gives the muscle the energy to move and is converted to adenosine diphosphate (ADP), then comes the creatine phosphate, and the ADP gives the phosphate atom, which charges it and This makes it the second adenosine triphosphate, which is still active. Give its energy to the muscles to keep moving.

Energy stores in the body

While adenosine triphosphate (ATP) and creatine phosphate (KRP) work inside muscle cells and provide it with energy, glycogen (glycogen stores), fat and protein from other stores provide energy to working muscle cells. Can do The energy reserves in the body vary greatly from the amount of energy available in them and from each other in terms of how long it takes to supply energy to the muscles. The following table gives the differences between the substances available to supply energy to the muscles.

1) When transporting a bag within 3 meters, it takes 3 seconds: ATP.

2) When you transport the bag 15 meters, it takes about 10 seconds: ATP is followed by creatine phosphate.

3) You are a weight-bearing athlete, lifting 80 kg of weight at once (within 30 seconds, for example): you consume ATP, KrP and a portion of glucose.

4) You are a weight-bearing athlete, you lift a weight of 80 kg several times, including breaks (a total of half an hour, for example): every time you consume ATP, KrP, glucose and a portion of glycogen. Repetition of the exercise is anaerobic, so the lactic acid increases, and you feel the stinging of the muscles because of it, and you have to stop the exercise.

5) You are a 100m runner: you consume ATP followed by creatine phosphate.

6) You are a marathon runner who runs two hours: In the first half an hour you consume ATP, KrP, glucose, and part of glycogen, then the body adjusts and stops the consumption of glucose and glycogen and you continue the marathon by consuming part of the fat. And due to the energy density in fat (9 large calories / gram of fat) and the abundance of fat in your body, you can run for days using fat energy.

Adenosine Triphosphate (ATP)

Adenosine triphosphate is a factor that provides energy for muscles to contract and work, and this is only for 2 seconds, and this is enough energy for three contractions. Even if it was assumed that ATP was given all its energy and converted to AMP, there would be 6 mmol / kg of muscle ATP stores remaining in the muscle.

If we know that the body consumes about 70 kilograms of ATP per day, which is equivalent to the weight of a person, then it is surprising that ATP is very important for muscle contraction and functioning, as it is the only direct source of energy supply to cells, and it is present in that small amount in Muscle cells.

Creatine Phosphate (KrP)

Since the ATP reserve in the muscle is only sufficient for 3 contractions (within 2 seconds), the body is forced to reconstitute ATP again as an important biomaterial. Here, creatine phosphate plays an important role, and it is an energy-rich chemical compound (meaning, more precisely, it has energy-rich bonds) and that bond is the bond between creatine and the phosphate atom. That chemical bond between phosphate and creatine fits the shot that ATP needs. By means of a rapid reaction to restore the formation of ATP, they are:

ADP + creatine phosphate ATP + creatine

(The reaction here runs from right to left.)

Where phosphate is separated from creatine phosphate and its combination with adenosine diphosphate, this restores adenosine triphosphate secondly and becomes ready to supply a new movement.

Moreover, creatine phosphate is present in amounts 3 to 4 times greater than the number of ATP in the muscle cell. . That is, the stock of creatine phosphate is also very important in terms of muscle adequacy to exert effort, as muscle contraction takes about 10 seconds (for non-athletes 6 seconds, and it reaches between 12-20 seconds for trainees)> so creatine phosphate is always in a sufficient position to supply ATP and thus supply Muscle energy. Moreover, creatine phosphate is the substance that regenerates ATP, until another reaction begins, after a short time, combing and participating in providing energy for the muscles to carry out their movement.

We know from experience that the amount of creatine phosphate in a muscle cell depends on the intensity of the existing movement as well as on its duration. If very intense movement is required, this may consume almost all of the stock of creatine phosphate, and after the end of the movement effort, the cell is replenished with energy again as quickly as possible. If this occurs and the follow-up to the energy supply from the energy-rich phosphate is delayed, the muscle stops working and cannot continue to contract and perform the movement. We feel that we need time to rest and regain strength.

Glucose

In a healthy person, the blood contains a certain percentage of glucose in a certain area that does not increase or decrease (see blood sugar). And if part of that sugar is used to provide energy to the muscles, then that sugar is replaced without being felt by glycogen and fat stores.

Glycogen

Glycogen is a type of glucose that the body prepares to be stored. Glycogen can store as muscle glycogen in the muscles (about 5 and 1 gram & 100 grams of muscle tissue), and part of the glycogen is stored in the liver. The amount of glycogen stored in the liver is estimated to be 75 to 90 grams, and it is used to control the level of sugar in the blood (80 - 100 mmol / dL). It thus maintains the proper functioning of the nervous system. And since the nervous system, as well as the brain and kidneys, depend on glucose to supply it with constant energy and store it slightly in the form of glucogen, the liver insures blood supply by about 60% of its percentage in the blood to ensure the work of the brain.

In the case of long-term moderate exertion (such as running) the muscles use the circulating sugar in the blood and thus the liver glycogen for movement. Research conducted by "Cogan" in 1990 showed that after 90 minutes of exertion with about 60% of the maximum oxygen capacity of VO2max, the oxidation of blood glucose constitutes about one third of the oxidation of carbohydrates.

When glycogen stores in the liver are about to run out, blood sugar levels drop, and if it falls below 70 below its normal level, it can cause imbalance and possibly dizziness. Is. That is why, when heavy glucose consumption occurs, the body adapts to itself and reduces glucose consumption to ensure that glucose is available to the brain. With this, the concentration of insulin in the blood decreases, and this hormone works to regulate the entry of glucose into the cells, and therefore due to constant effort and a decrease in glycogen stores, blood sugar levels are approx. The drop may fall. At calm, 50% of its normal level. Furthermore, due to this constant effort, the liver can rely on proteins such as alanine or glycerin to obtain glucose through a process of metabolism called "glucogenesis renewal".

In the case of strenuous exercise during the competition, for example, glucose reserves in the body can remain for 60 to 90 minutes to supply muscles with glucose.

Fat

Fat is found under the skin in body tissues (and is an important store), and it is also found in muscle cells in the form of triglycerides. Triglyceride molecules are made up of glycerin molecules and are bound to three fatty acids. Some fatty acids are free-floating in the blood and can be oxidized in all cells of the body. In muscle cells, the oxidation process takes place primarily during which the chains of fatty acids break down (usually consisting of long carbon chains containing 12 to 18 carbon atoms), and broken down into smaller molecules. Are two of which are carbon atoms. These molecules are called acetyl-CoA. These short molecules enter the cell's mitochondria, and this is called the citric acid cycle. But this reaction is slow so that the part of the energy generated by this process is used to work the muscles. Gets ready, doesn't last long. With the continuation of this great physical effort, the percentage of its use decreases. Muscle triglyceride content is between 3 and 0-8 and 0% of muscle size. Fatty acids are released by the absorption of water triliseride molecules. This disorder of triglycerides occurs when the kidneys release adrenaline and noradrenaline, hormones that are cursed by extreme physical exertion. But it also reduces the formation of lactic acid in the blood. The concentration of lactic acid in the blood significantly reduces the concentration of fatty acids in the blood between 5-8 mm / liter.

The oxidation of fats and the release of energy from them to the muscles depends on the duration of the effort, the intensity of the exertion, and the amount of glycogen stored in the muscle. The body begins to use subcutaneous fat when the glycogen stores are low and the long or moderate intensity is attempted, then it starts after 15-30 minutes of walking at an average speed, for example. And long hours of training play an important role here, as it increases energy savings by burning fat for mobility and reducing the consumption of carbohydrate stores.

Fats carried in the blood are an intermediate part of the energy supply to the muscles. During the metabolism of sugar, muscle cells are also able to extract energy directly from fat.

Protein

See also protein metabolism

During the process of metabolism, dietary protein is broken down into amino acids, a simple protein structure that the body can exploit in its own way and compensate and repair the corrupt. As far as the use of proteins for body production is concerned, except that it does not occur in most cases, such as prolonged starvation, or an event of starvation in which food is scarce, or excessive. This is important for athletes when running long distances. More than 90 minutes and muscle glycogen storage is reduced, so body protein can be 5 to 5 to 15% of the body's total energy.

Oxidation of amino acids is associated with an increase in blood urea, for example it can be measured after a long walk. At the same time, the concentrations of the amino acids leucine, isoleucine and valvine decrease, indicating their participation in the oxidative process in the muscles. In extreme cases, just as a person stays in the mountains for long periods of time, the human body can also indirectly exploit a portion of muscle protein, ie the body digests itself. Of course, this is not necessary for athletes, as they are generally interested in building and strengthening their muscles.