CHOLESTEROL

cholesterol/3-hydroxy-5-6-cholestene

• is an unsaturated steroid alcohol containing four rings, and it has a single c-h side chain tail similar to fatty acid

cholesterol ester

• 70%

• found in plasma and serum

• this cholesterol is bound to fatty acid (hydrophobic form)

• found on the surface of lipid layers but are located in the center of lipid drops, an lipoprotein along with TAG

• undergoes esterification by LCAT

lecithin-cholesterol acyl transferase (lcat)

• synthesized in liver

• enables hdl to accumulate cholesterol as cholesterol ester

apoA1

• activator of lcat and key component of cholesterol transport

• the most abundant protein in hdl, it modulates interactions that affect hdl’s cardio protective functions, in part via its activation of the enzymes, lcat

free cholesterol

• 30%

• found in plasma and serum and rbcs

• polar non esterfied alcohol

• free cholesterol and phospholipids are found on the surface of lipoproteins

libermann burchardt reaction

• based on the reaction of cholesterol with acetic acid anhydride and conc. sulfuric acid. producing green color rnx

• the intensity of green color is directly proportional to the amount of cholesterol present in the sample

salkowski reaction

• the earliest colorimetric chemical rnx for qualitative and quantitative determination of cholesterol

• color change produced when cholesterol reacts with concentrated sulfuric acid