Fats are found in both animals and plants. They are esters of trihydric alcohol (glycerol) and acids (oleic, stearic, linoleic, linolenic and palmitic). This is proved by their breakdown into acids and glycerol, as well as by the synthesis of fats from the described compounds.
Formation of fats in the human body
Fats are esters of glycerol. During the digestive process, they are emulsified by bile s alts and come into contact with enzymes, with the help of which they are hydrolyzed. Thus, the released fatty acids are absorbed into the mucosa of the digestive tract, which is the end of the fat synthesis process. The fat then travels throughout the body's portal system as microparticles that bind to proteins in the blood. Metabolism occurs in the liver.
Fat synthesis is possible due to excess carbohydrates that are not involved in the formation of glycogen. In addition, lipids are derived from certain amino acids.
In comparisonwith glycogen, fats are compact energy storage. However, it is not limited in any way, since it has the form of neutral lipids in fat cells. Lipogenesis occurs due to the synthesis of fatty acids, as they are found in almost all lipid groups.
Stages of lipid metabolism
Fats and fat-like compounds go through the following cycle in the human body:
- ingestion with food;
- breakdown into simpler compounds, digestion process, absorption;
- transferred from the digestive system by chyloproteins;
- metabolism of a complex protein represented by neutral fats, fatty acids, cholesterol or phospholipids;
- metabolism of complex lipids, esters of polyhydric alcohols and higher fatty acids;
- polycyclic lipophilic alcohol exchange;
- transition of fatty acids and ketone bodies;
- the process of converting acetyl-CoA into fatty acids;
- breakdown of fats into components under the action of lipase;
- degradation of fatty acid breakdown products.
The importance of fatty acids for the human body
Phospholipids are important for normal fat synthesis in the human body. With their lack, metabolic processes in the liver are inhibited.
Phospholipids break down into glycerol, fatty acids, phosphoric acid and nitrogenous bases. The first two substances can either be converted into water and carbon dioxide, or participate in the synthesis of fats.
Choline (a nitrogenous base) is important for educationmethionine and creatine. Methionine is necessary for the normal functioning of the liver, lowering cholesterol levels in the blood, as well as an antidepressant effect. Creatine is responsible for energy metabolism in muscle and nerve cells. Acetylcholine (a product of choline) normalizes the transmission of nervous excitation.
It is fats that provide energy to adesine triphosphate molecules that are responsible for all biochemical processes in the body.
Thus, the synthesis of fats in cell membranes is important for the occurrence of numerous chemical reactions. Without them, the human body will not be able to function normally.
Causes of fat digestion disorders
Failures in the absorption of fats can be caused by the following reasons:
- Bile duct obstruction leading to problems with secretion. This condition may be caused by the presence of stones or tumors. Reduced production of biliary secretion leads to difficulty in mixing fats and thus inability to hydrolyze fatty compounds.
- Problems with the production of juice in the pancreas. It also affects the hydrolysis of fats.
Each of the problems described above leads to an increase in the amount of fat in solid human waste products. There is a so-called "fat stool". This condition is fraught with the fact that fat-soluble vitamins A, E, D and K, as well as essential fatty acids for the body, are no longer absorbed. Prolonged "fatty stools" lead to deficiency of these substances and the development of corresponding clinical symptoms.
Also, the failure of fat digestion leads to difficulties in the absorption of non-lipid substances, since fat tends to envelop food, which prevents enzymes from affecting it.
Diseases caused by failure of fat synthesis
Impaired lipid metabolism can lead to the following conditions:
- Obesity. It occurs both in violation of eating habits associated with a sedentary lifestyle, and in the presence of hormonal imbalance.
- Abetalipoproteinemia. A rare hereditary disease in which certain lipoproteins are missing from the blood. Fats accumulate in the mucosa. Deformation of erythrocytes develops.
- Cachexia. Low calorie intake leads to a decrease in adipose tissue in the body. This condition can occur in the presence of tumors, with chronic diseases of an infectious nature, poor nutrition or metabolic failures.
- Atherosclerosis. Chronic arterial disease caused by impaired lipid metabolism, associated with the deposition of cholesterol plaques on the vascular walls. In the future, this is fraught with the appearance of sclerosis (proliferation of connective tissue), which leads to deformation of the vessels up to their complete blockage. Atherosclerosis provokes coronary heart disease.
- Menckeberg's arteriosclerosis. This disease is similar to atherosclerosis. However, its fundamental difference is that the vessels are deformed and clogged not under the influence of connective tissues, but due to calcification - accumulation of s alt deposits. With such a lesion, they do not formplaques. In addition, the disease provokes other complications, the main of which is aneurysm.
Synthesis of fats in plant cells
Exchange processes in plant tissues undergo changes at the end of the flowering period. When protein synthesis weakens, fats begin to form from carbohydrates. This process proceeds until the full ripening of the seeds. The synthesis of fats from carbohydrates and the synthesis of proteins from amino acids are important for the breeding season.
Oilseeds are characterized by the highest fat content. This must be taken into account by those who wish to adjust their own weight.
Lipid metabolism in science
Today, the synthesis of fats suitable for nutrition is possible through the esterification of fatty acids with glycerol, which, in turn, are created by the oxidation of paraffins. Since both fatty acids and glycerol are obtained from coal, there is a real way to carry out the complete synthesis of dietary fats. These discoveries became possible thanks to the works of F. Wöhler, A. V. G. Kolbe, M. Berthelot and A. M. Butlerov. It was they who proved the connection between organic and inorganic substances, as well as the possibility of their interconversion.
The acquired knowledge is successfully applied in the food, pharmaceutical and chemical industries. However, today it is more expedient to obtain fats from natural sources (vegetable and animal), since synthesis is not a profitable economic procedure.
