Unsaturated steroid alcohol in our blood cells is called Cholesterol.
70 to 80 percent of cholesterol in the plasma are esterified with long chain saturated and unsaturated fatty acids, why 20 to 30 percent exist as free unesterified cholesterol.
Function of Cholesterol
Metabolic precursor for the biosynthesis of bile acids, and steroids hormones, includes male and female sex steroids (androgen and oestrogens) and adrenal steroid hormones ( aldosterones and corticosterone, are the major function of Cholesterol.
Liver, ovaries, testes and adrenal glands synthesise these hormones using cholesterol as the main precursor.
Cholesterol is a major structural components of cell membranes.
As results of it insurability in water, Cholesterol can also help control flow of water soluble products in and out of cells.
In human, 60 to 70 percent of Cholesterol is transported by low density lipoprotein, (LDL), 20 to 35 percent by High Density Lipoprotein (HDL), and 5 to 12 percent by very low Density Lipoprotein (VLDL).