CHEM 153C Study Guide - Final Guide: Sterol Regulatory Element-Binding Protein, Endoplasmic Reticulum, Ester
21 Jun 2016
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Document Summary
Deposition of excess cholesterol in the circulatory system can give rise to three medical problems: heart disease, stroke, atherosclerosis. Ldl is taken up by cells via receptor-mediated endocytosis. Hmg-coa reductase: camp-dependent and independent reductase kinases phosphorylate enzyme leading to inactivation. The role of the mammalian liver in maintaining cholesterol homeostasis: The liver regulates blood cholesterol levels by controlling how much cholesterol is made available to the peripheral tissues and disposing of excess cholesterol as bile acids. Dietary cholesterol is delivered to the liver via chylomicrons or chylomicron remnants. The liver synthesizes any additional cholesterol needed by the peripheral tissues or for bile acid production. Dietary and synthesized cholesterol are packaged and delivered to the peripheral tissues by vldls, idls, and ldls. Excess cholesterol is returned to the liver by hdls. The liver then adjusts the rate of cholesterol synthesis and bile acid production to meet the needs of the organism. Excess cholesterol is converted to bile acids and excreted.
