How do LDL and HDL differ structurally and functionally?

The thing that separates HDL from LDL functionally is how they react with the body. LDL is perceived as the bad or villain cholesterol because having a lot of it in your body can lead to plaque build-up in your body that can result in health problems such as heart disease. HDL is perceived as the good or hero cholesterol because it absorbs cholesterol and returns it to the liver which the liver will then take care of it to rid it from the body. On the structural side of things, HDL is different from LDL because its composition because HDL has more proteins than LDL and LDL has more fat. Which is where their names derive from, High Density and Low Density lipoprotein. The excess of protein in the HDL is what makes it high density and the excess of fat in the LDL makes it lower density.

sources for this section: CDC. "LDL and HDL: “Bad” and “Good” Cholesterol." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 16 Mar. 2015. Web. 21 Apr. 2017.