Cholesterol, triglycerides, and high-density lipoproteins are important constituents of the blood lipids fraction of the human body.
Cholesterol is an unsaturated alcohol of the steroid family of compounds; it is essential for the normal function of all animal cells and is a fundamental element of their cell membranes. Cholesterol is a fatty substance produced by the liver and carried by the blood to supply material for cell walls and hormones. It is also a precursor of various critical substances such as adrenal and gonadal steroid hormones and bile acids.
Cholesterol is a type of fat, and fats can’t travel in the blood on their own. They need to be attached to proteins. Lipoproteins are little parcels made of fats and proteins that carry fats around the body. Lipid is another name for fat, so ‘lipoprotein’ means fat plus protein.
In the human bloodstream, triglycerides play an important role in metabolism as an energy source and in helping to transfer dietary fat throughout the body. They contain more than twice as much energy as carbohydrates, the other major source of energy in the diet.
When eating, human body converts any calories it does not need to use right away into triglycerides, which are stored in body fat cells. When body need energy between meals, hormones trigger the release of some of these stored triglycerides back into the bloodstream.
Blood lipids
