large lipids are packaged in chylomicrons for absorption in the small intestine.
large lipids are packaged in chylomicrons for absorption in the small intestine.
where are large lipids packaged in chylomicrons for absorption?
small intestine
chylomicrons are formed in the endoplasmic reticulum in the absorptive cells (enterocytes) of the small intestine. the villi, lined with the microvilli of the brush border, provide a lot of surface area for absorption. newly formed chylomicrons are secreted through the basolateral membrane into the lacteals, where they join lymph to become chyle. the lymphatic vessels carry the chyle to the venous return of the systemic circulation. from there the chylomicrons supply the tissue with fat absorbed from the diet. thus, unlike the saccharides and amino acids that digestion liberates from the carbohydrates and proteins of the diet (respectively), the lipids from the diet bypass the hepatic portal system, meaning the liver does not get "first crack" at them.
chylomicron
apob48 is identical to the amino terminal 48% of apob100. the function of this isoform is in fat absorption of the small intestine and is involved in the synthesis, assembly and secretion of chylomicrons. these chylomicrons transport dietary lipids to tissues while the remaining chylomicrons along with associated residual lipids are in 2–3 hours taken up by the liver via the interaction of apolipoprotein e (apoe) with lipoprotein receptors. it is the dominant apob protein in the small intestine of most mammals. it is a key protein in the exogenous pathway of lipoprotein metabolism. intestinal proteins containing apob48 are metabolised to chylomicron remnant particles which are taken up by remnant receptors.
apolipoprotein b