substances including coenzymes which must be present in many eniymatic

substances including coenzymes which must be present in many eniymatic reactions, in their absence the enzymatic reaction cannot proceed) Thus apo I is a cotactor of lecilhm cholesterol acyl transtecase (LCAT) ativity, CM acts as a cofactor for lipoprotein lipase activity Genetic absence of CM in a family causes the disease familial hypercholesTeremia (b) bin from the pom! of view of medical students the most important fact is that because of the presence of these apoli pop roleins, the hpoproteins can combine with their specific race plots of the largal cells (and subsequently metabolized) Thin apo B binds with LDL and the LDL now can bind with its receptor it is hightly possible that abnormalities of these of such diseases like atherosclerosis and hyperchotesteremia. Structure of a lipoprolein [NB To keep the discussion simple, only 4 classes of lipoproteins have been mentioned above Most authors now include IOL {intermediate density lipoprol em) in addition lo the above 4 categories) Upoprotem lipase. After a meal very rich in fat. the plasma becomes milky. This milkiness is due ret the presence of exces s amount of chylomicron particles In the plasma In due time, or following a heparin injection, the plasma is cleared of its milkiness. This clearing is due to the activity of a clearing factof (.an enzyme] called plasma lipoproiem hpate As a result or the action of this enzyme, the Inglycenda portion of the lipoprotein is hydrulyzed to glycerol and free fatty acids (FFA) Most of the FFA rhus formed enter the ertrahepatic tissues (like the muscles, where they are catabolized) This causes clearing of the plasma. The anginal chylomrcron panicle therefore now becomes much smaller, and contains tha protein cholesterol and phospholipid portions but practically no Inglyceride