<P> Hydrolysis by hepatic lipase releases glycerol and fatty acids, leaving behind IDL remnants, called low - density lipoproteins (LDL), which contain a relatively high cholesterol content (see native LDL structure at 37 ° C on YouTube). LDL circulates and is absorbed by the liver and peripheral cells . Binding of LDL to its target tissue occurs through an interaction between the LDL receptor and apolipoprotein B - 100 on the LDL particle . Absorption occurs through endocytosis, and the internalized LDL particles are hydrolyzed within lysosomes, releasing lipids, chiefly cholesterol . </P> <P> Lipoproteins may be classified as follows, listed from larger and less dense to smaller and denser . Lipoproteins are larger and less dense when the fat to protein ratio is increased . They are classified on the basis of electrophoresis, ultracentrifugation and nuclear magnetic resonance spectroscopy via the Vantera Analyzer . </P> <Ul> <Li> Chylomicrons carry triglycerides (fat) from the intestines to the liver, to skeletal muscle, and to adipose tissue . </Li> <Li> Very - low - density lipoproteins (VLDL) carry (newly synthesised) triglycerides from the liver to adipose tissue . </Li> <Li> Intermediate - density lipoproteins (IDL) are intermediate between VLDL and LDL . They are not usually detectable in the blood when fasting . </Li> <Li> Low - density lipoproteins (LDL) carry 3,000 to 6,000 fat molecules (phospholipids, cholesterol, triglycerides, etc .) around the body . LDL particles are sometimes referred to as "bad" lipoprotein because concentrations, dose related, correlate with atherosclerosis progression . <Ul> <Li> large buoyant LDL (lb LDL) particles </Li> <Li> small dense LDL (sd LDL) particles </Li> <Li> Lipoprotein (a) is a lipoprotein particle of a certain phenotype </Li> </Ul> </Li> <Li> High - density lipoproteins (HDL) collect fat molecules (phospholipids, cholesterol, triglycerides, etc .) from the body's cells / tissues, and take it back to the liver . HDLs are sometimes referred to as "good" lipoprotein because higher concentrations correlate with low rates of atherosclerosis progression and / or regression . </Li> </Ul> <Li> Chylomicrons carry triglycerides (fat) from the intestines to the liver, to skeletal muscle, and to adipose tissue . </Li>

What are the four major types of plasma lipoproteins