What is cholesterol for ?
Cholesterol is a fatty substance in blood that is essential to human life because it is instrumental in building and repairing cells, the production of sex hormones like estrogen and testosterone, converting bile acids to aid in digestion of food and the production of vitamin D. Cholesterol is manufactured by the liver and other organs and consumed via animal fat. In the human body large amounts of cholesterol are found in brain and nerve tissue. The brain needs a lot of fat, it is the fattiest organ in the body, because fat is an essential component of nerve cells and their insulating covering (a substance called |
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myelin), without which the electrical signals that run along the nerve fibres would dissipate into the surrounding tissues. Cholesterol plays a central role in many biochemical processes, but is best known for the association of heart disease with various lipoprotein cholesterol transport patterns in the blood.
What is cholesterol made of ?
Cholesterol is a steroid, a lipid (more commonly known as a fat), and an alcohol, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. Most does not come from the diet, it is synthesized internally. It is present in higher concentrations in tissues which either produce more or have more densely packed membranes; for example the liver, spinal cord, brain and atheroma.
What is cholesterol like
It is a soft waxy substance that is minimally soluble in water; it cannot dissolve and travel in the water-based bloodstream. Instead, it is transported in the bloodstream by lipoproteins; protein which are water soluble and carry cholesterol and fats internally. The proteins forming the surface of the given lipoprotein particle determine from what cells cholesterol will be removed and to where it will be supplied.
What is cholesterol doing in the body
Cholesterol travels around your body in the blood stream as serum or plasma cholesterol. Serum or plasma is the watery part of the blood that remains after the red and white blood cells have been removed. In order to travel through the blood it is coated in a protein and the resultant molecule is called a lipoprotein. The lipoproteins carry the cholesterol throughout the body where it is used where needed. Cholesterol is an important component of the membranes of cells, providing stability; it makes the membrane's fluidity stable over a bigger temperature interval. The hydroxyl group on cholesterol interacts with the phosphate head of the membrane and the bulky steroid and the hydrocarbon chain is embedded in the membrane. It is the major precursor for the synthesis of vitamin D, of the various steroid hormones, including cortisol, cortisone, and aldosterone in the adrenal glands, and of the sex hormones progesterone, estrogen, and testosterone. The presence of cholesterol has a direct effect on the fluidity of the membrane. Further recent research shows that it has an important role for the brain synapses as well as in the immune system, including protecting against cancer.
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