Lee Chong Wei outclassed at Beijing Olympics 2008

So our national champ lost to Lin Dan, world no.1 in badminton. Better luck next time Chong Wei...

on a different note, i think this is one of the questions i didn't do too well.

High Density Lipoprotein (HDL) is sometimes referred to as “good cholesterol” because it is involved in returning cholesterol from peripheral tissues to the liver from where it can be eliminated from the body. Describe how HDL carries out this function. Include mention of how cholesterol is picked up by HDL and the three ways in which that cholesterol is transferred to the liver. What is the major health problem caused by elevated cholesterol in the blood?

Answer:
The ABC1 protein on peripheral cells transfers cholesterol to the HDL particle. Within HDL, lecithin-cholesterol acyl transferase (LCAT) attaches an acyl chain to the cholesterol molecule and the cholesterol ester sinks into the interior of the particle.
The cholesterol may be transferred to the liver in 3 ways
1. Cholesterols esters may be transferred to remnant particles (VLDL and chylomicron) via the cholesterol ester transfer protein, and the remnant particles are taken up into liver cells.
2. cholesterol esters may be transferred to liver cells directly via a scavenger receptor – this transfer does not require endocytosis
3. HDL particles with high amounts of apoE may be endocytosed into liver cells
The major health problem caused by elevated plasma cholesterol is atherosclerosis. This is particularly due to elevated LDL. Macrophages have “scavenger” receptors which allow them to engulf LDL particles – these receptors have low affinity and thus function more efficiently at higher LDL levels. Such macrophages may deposit their load of cholesterol as a “fatty streak” at sites of damage in arterial walls. Eventually, the deposits may build up enough to prevent blood flow and thus cause tissue damage due to oxygen deprivation.