Cholesterol is an organic molecule. It is a sterol (or modified steroid), a lipid molecule and is biosynthesized by all animal cells because it is an essential structural component of all animal (not plant or bacterial) cell membranes that is required to maintain both membrane structural integrity and fluidity.Cholesterol enables animal cells to not need a cell wall (like plants and bacteria) to protect membrane integrity and cell viability, thus are able to change shape and move about (unlike bacteria and plant cells which are restricted by their cell walls).
In addition to its importance within cells, cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acids, and vitamin D. Cholesterol is the principal sterol synthesized by animals. All kinds of cells in animals can produce it. In vertebrates the hepatic cells typically produce greater amounts than other cells. It is almost completely absent among prokaryotes (bacteria and archaea), although there are some exceptions such as Mycoplasma, which require cholesterol for growth.
Cholesterol functions as an insulating cover for the transmission of electrical impulses in the nervous tissue. Cholesterol is required to build and maintain membranes; it modulates membrane fluidity over the range of physiological temperatures. The hydroxy group on cholesterol interacts with the polar head groups of the membrane phospholipids and sphingolipids, while the bulky steroid and the hydrocarbon chain are embedded in the membrane, alongside the non-polar fatty-acid chain of the other lipids. Through the interaction with the phospholipid fatty-acid chains, cholesterol increases membrane packing, which reduces membrane fluidity. The structure of the tetracyclic ring of cholesterol contributes to the decreased fluidity of the cell membrane as the molecule is in a trans conformation making all but the side chain of cholesterol rigid and planar. In this structural role, cholesterol reduces the permeability of the plasma membrane to neutral solutes, hydrogen ions, and sodium ions.
Within the cell membrane, cholesterol also functions in intracellular transport, cell signaling and nerve conduction. Cholesterol is essential for the structure and function of invaginated caveolae and clathrin-coated pits, including caveola-dependent and clathrin-dependent endocytosis. The role of cholesterol in such endocytosis can be investigated by using methyl beta cyclodextrin (MβCD) to remove cholesterol from the plasma membrane. Recent studies show that cholesterol is also implicated in cell signaling processes, assisting in the formation of lipid rafts in the plasma membrane. Lipid raft formation brings receptor proteins in close proximity with high concentrations of second messenger molecules. In many neurons, a myelin sheath, rich in cholesterol, since it is derived from compacted layers of Schwann cell membrane, provides insulation for more efficient conduction of impulses.
Within cells, cholesterol is the precursor molecule in several biochemical pathways. In the liver, cholesterol is converted to bile, which is then stored in the gallbladder. Bile contains bile salts, which solubilize fats in the digestive tract and aid in the intestinal absorption of fat molecules as well as the fat-soluble vitamins, A, D, E, and K. Cholesterol is an important precursor molecule for the synthesis of vitamin D and the steroid hormones, including the adrenal gland hormones cortisol and aldosterone, as well as the sex hormones progesterone, estrogens, and testosterone, and their derivatives.
Some research indicates cholesterol may act as an antioxidant.
So now you can understand that cholesterol can have serious consequences on your health, here you will find out how to keep it under control until the problem will get even more serious. Here are also some aliments that should not lack from your daily menu if you have problems with the cholesterol. In the first place, you should eat eggs because they are containing vitamins B12 and D. The olive oil can be good as well because the cholesterol is caused by the fat produced by the liver but also from the fat of aliments. You have to avoid the consuming of fat aliments and you could replace the butter with the olive oil. You should also consume peanuts and nuts because they can reduce the level of cholesterol. The nuts and peanuts are poor in saturate fat and omega 6, but they are rich in polyphenol and this is the winning combination of the inflammation reducing. You should also eat yogurt because some studies have demonstrated that the persons which are consuming lactates daily, have a low-fat, with a reduced risk of heart diseases. The yogurt has a high level of calcium, proteins and a variety of vitamins. The processed cereals can increase the level of DLD, on the other hand, the integral cereals are rich in vitamins, minerals and antioxidants and also fibers that can stronger the immunity system and the body health in general. Seafood can be helpful as well. The fish of cold water can improve the healthy of your hearts thanks to its big containing of omega 3, which reduces inflammations and also reduces the level of LDL. The category of fishes which contains a high level of omega 3 is including mackerel, salmon, herring and also sardines. In order to keep your arteries healthy, you don’t have to give up on chocolate. The consume of chocolate can improve the level of HDL and can reduce the one of LDL. But, because the chocolate products are rich in sugar, you have to chose the black chocolate which also has more nutritional benefits. Lean red meat have been proved to be really beneficial, by some recent studies which showed up that this kind of meat is really good for the healthy of the cardiovascular system. Also, seeds are containing beneficial nutrients for the organism’s healthy. In addition to this, they also have fibers and proteins which are controlling the appetite. The rich diet of seeds can improve the report between LDL and HDL. The researchers says that this happens thanks to the antioxidants proprieties of seeds.