ATP (Adenosine triphosphate) 20 mg. №40 tablets
ATP (adenosine triphosphate: adenine associated with three phosphate groups) is a molecule that serves as a source of energy for all processes in the body, including movement. The contraction of muscle fiber occurs with the simultaneous cleavage of the ATP molecule, resulting in the release of energy that goes into effecting the contraction. In the body, ATP is synthesized from inosine.
ATP has to go through several steps to give us energy. First, with the help of a special coenzyme, one of the three phosphates (each of which gives ten calories) is separated, energy is released and adenosine diphosphate (ADP) is obtained. If more energy is required, then the next phosphate is released, forming adenosine monophosphate (AMP). The main source for the production of ATP is glucose, which in the cell is initially split into pyruvate and cytosol.
During rest, the reverse reaction occurs - with the help of ADP, phosphagen and glycogen, the phosphate group rejoins the molecule to form ATP. For these purposes, glucose is taken from glycogen stores. The newly created ATP is ready for next use. In essence, ATP works as a molecular battery, conserving energy when it is not needed and releasing it when needed.
The structure of ATP:
An ATP molecule consists of three components:
1. Ribose (the same five-carbon sugar that forms the basis of DNA)
2. Adenine (conjugated carbon and nitrogen atoms)
The ribose molecule is located in the center of the ATP molecule, the edge of which serves as a base for adenosine. The chain of three phosphates is located on the other side of the ribose molecule. ATP saturates long, thin fibers that contain a protein called myosin, which forms the basis of our muscle cells.
ATP reserves are sufficient only for the first 2-3 seconds of locomotor activity, however, muscles can only work in the presence of ATP. For this purpose, there are special systems that constantly synthesize new ATP molecules, they are activated depending on the duration of the load (see figure). These are the three main biochemical systems:
1. Phosphagenic system (Creatine phosphate)
2. Glycogen and lactic acid system
3. Aerobic respiration
When the muscles are short but intense (about 8-10 seconds), a phosphagenic system is used - ADP is combined with creatine phosphate. The phosphagenic system ensures the constant circulation of a small amount of ATP in our muscle cells. Muscle cells also contain high-energy phosphate - creatine phosphate, which is used to restore ATP levels after short-term, high-intensity work. The enzyme creatine kinase takes away the phosphate group from creatine phosphate and quickly transfers it to ADP to form ATP. So, a muscle cell converts ATP to ADP, and phosphagen quickly restores ADP to ATP. The level of creatine phosphate begins to decrease after 10 seconds of high-intensity activity. An example of using a phosphagen power system is a 100m sprint.
Glycogen and lactic acid system
The glycogen and lactic acid systems provide energy to the body more slowly than the phosphagen system, and provide enough ATP for about 90 seconds of high-intensity activity. During the process, the formation of lactic acid occurs as a result of the anaerobic metabolism of muscle cells.
Considering the fact that in the anaerobic state the body does not use oxygen, this system gives short-term energy without activating the cardio-respiratory system in the same way as the aerobic system, but with time savings. Moreover, when in anaerobic mode, the muscles work quickly, they contract very strongly, blocking the flow of oxygen, as the vessels are contracted. This system can still be called anaerobic-respiratory, and a good example of how the body works in this mode is a 400-meter sprint. Usually to continue to work in this way athletes are not given the muscle soreness resulting from the accumulation of lactic acid in the tissues.
If the exercise lasts for more than two minutes, the aerobic system is put into the work, and the muscles get ATP first from carbohydrates, then from fat and finally from amino acids (proteins). Protein is used to produce energy mainly in conditions of hunger (diets in some cases). In aerobic respiration, ATP production is slowest, but energy is obtained enough to maintain physical activity for several hours. This is because glucose breaks down into carbon dioxide and water unobstructed, without being counteracted by, for example, lactic acid, as in the case of anaerobic work.