Question

What is formed first from the discoidal HDL in reverse cholesterol transport?

a) HDL-2
b) HDL-3
c) LDL
d) VLDL

Answer 1

In reverse cholesterol transport, HDL-3 is the first spherical form of high-density lipoproteins formed from discoidal HDL, which scavenges excess cholesterol from cells and evolves into HDL-2.

Step-by-step explanation:

In the process known as reverse cholesterol transport, high-density lipoproteins (HDL) play a crucial role in removing cholesterol from peripheral tissues and transporting it back to the liver. Initially, the immature HDL particles, or discoidal HDL, are formed which then evolve into spherical HDL particles. The first spherical form of HDL that is formed from discoidal HDL during reverse cholesterol transport is HDL-3.

The primary function of HDL-3 is to scavenge excess cholesterol from cells and other lipoproteins, including low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL). Over time and with the acquisition of more cholesterol and phospholipids, HDL-3 may mature into HDL-2, which has a larger size and higher cholesterol content.