Biochemistry/Complex Lipid Metabolism and Cholesterol

Introduction

Dietary serve a variety of function in the body. One of the most important function is as a metabolic fuel, per gram, fats yield twice as much energy as carbohydrate. All steroid hormones are derived initially from lipid, and these in turn are responsible for the regulation of body functions such as growth, development and the appearance of sexual characteristics as a result of sex hormones. Essential fatty acids, such as linoleic acid and α-linolenic acid are prostaglandin and ecosanoid precursors.

Digestion and Absorbtion of Lipids

Lingual Lipase

Short Chain Fatty Acids

Long Chain Fatty Acids

Bile

Primary Bile Acids Bile Salts Secondary Bile Acids

Chylomicron Formation

Micelles

Low Density Lipoprotein (LDL)

Low density lipoprotein (LDL) is known as bad cholesterol. When the level of LDL is high in the blood, it could slowly build up inside the arteries that pump the blood to the brain and the heart. LDL and other substances can cause atherosclerosis. Atherosclerosis is a disease that happened when the arteries became less flexible and narrow due to the plaque that LDL and other substances form.

High Density Lipoprotein (HDL)

Cholesterol can not dissolved in the blood there for it has to be transported in and out of the cells by carrier called lipoprotein. There are two type of lipoprotein: low-density lipoprotein ( LDL) and high-density lipoprotein HDL. high density lipoproteins (HDL) are known as good cholesterol because high level of HDL could prevent from heat attacks. Some scientists believe that high-density lipoprotein (HDL) slow the build up of plaque in which it removes cholesterol from arteries.