Lipids can either be in two dominant forms, exogenous or endogenous. This means the formation and creation either outside or inside the body respectively. Lipids then have to be transported to tissues and organs throughout the body to perform metabolic functions. Because of their hydrophilic nature, transportation requires hydrophilic adaptation. This allows a series of lipoproteins, called micelles, to transport them throughout the body.
Lipoproteins are outer monolayers of proteins and polar lipids with an inner core of neutral lipids.
The more important being LDL, because it is the bad cholesterol level and HDL, which is the wanted good cholesterol level. The first being cholesterol esters. They are the combination of small cholesterol molecules along with fatty acids that are esterified at the carbon three hydroxyl group. Once synthesized, cholesterol esters help transport cholesterol in complexes of lipoproteins. Cholesterol is then esterified into fatty acids by the enzyme Lecithin-Cholesterol Acyltransferase in plasma and by AcylCholesterol Acyltransferase intracelluarly.