Biochemistry

In combination with proteins, these substances are part of the nervous tissue, liver, heart muscle, and gonads . They participate in the construction of cell membranes, determine the degree of their permeability to fat-soluble substances, participate in the active transport of complex substances and individual ions into and out of cells, increase the activity of prothrombin , which is involved in blood coagulation processes. Glycerophospholipids contribute to the better use of protein and fat in tissues, participate in protein biosynthesis, and prevent fatty liver. Being antioxidants, they prevent the oxidation of other compounds, including vitamins A and E. Phosphatides, mainly lecithin, play an important role in the prevention of atherosclerosis of blood vessels. The daily human need for phospholipids is 5-6g . They are found in foods such as unrefined oils, butter, egg yolk. With a lack of these lipids in food and a low content of substances necessary for their synthesis, neutral fat is deposited in the liver tissue, which violates its functions. Glycerophospholipids are divided into the following groups (subclasses): 1) phosphatidylcholines (lecithins); 2) phosphatidylethanolamines (cephalins); 3) phosphatidylserines-, 4) acetal phosphatides (plasmalogens); 5) phosphatidylinositis. In the phosphatidylcholine molecule, the two carboxyl groups of glycerol (in the first and second positions) are replaced by fatty acid radicals (saturated and unsaturated), and one by phosphoric acid combined with a nitrogenous base , choline. CH 3 HO-CH 2 — сн 2 — Жсн 3 CH 3 Choline a - Lecithin Phosphatidylethanolamines (cephalins) differ from phosphatidylcholines in that they contain ethanolamine (colamine) instead of choline. ho - ch 2 - ch 2 - nh 2 Colamine (ethanolamine) CH — 0 — C-R ' £ СҢ — O — G-R CH — О — P — 0 — CHj — CHy~NH 2 OH a - Phosphatidylethanolamine 130