Self-reflection lipids (Qila)

Today, on 2 December 2019 for our biochemistry class we have learn about lipids. Lipids is a molecule that is soluble in organic solvent. Function of lipids are energy storage, biological membrane and intra and intercellular molecule. For lipids, it’s has 2 types of polarity which are non-polar and polar. For non-polar molecules  which normally use for energy storage is made of 1 glycerol and 3 fatty acids while for polar molecule is a basis of bilayer. There are a few groups of lipids that exist in this world. For example, fatty acids, triacylglycerols, glycerophospholipids, sphingolipids, isoprenoids.

The first group of the lipids is fatty acids. Fatty acids is a saturated chains pack tightly while unsaturated chains bend and pack in less ordered way. It’s is naturally occurring double bond. For the naming of the fatty acids, can be read by numbering. As example, 12:0 where 12 is number of carbon while 0 is the number of double bonds. Due to the fatty acids is saturated lipids so it does not have double bonds. The longer the size of the fatty acids, the higher the melting point. For the unsaturated lipids, the numbers will show like 20:4  where x depends on the location of the double bond. The more double bond that exist at in the structure, the lower the melting point of the molecule.

The second group of lipids is triacylglycerols (TAG). TAG is formed by the reaction between 1 molecule of glycerol and 3 molecules of fatty acids. Animals have higher percentage of the saturated fatty acid residues. TAG melting temperature is depending on the degree of saturation and chain length. The function of the TAG is as energy storage, heat insulation and saponification.

The third group of lipids is glycerophospholipids. It is the major lipid component of biological membrane such as our skin. Glycerophospholipids are amphiphilic molecules with non-polar aliphatic tails and polar phosphoryl-X heads. Glycerophospholipids can be degraded at various point by an enzyme (phospholipase). 

The forth group of lipids is sphingolipids which act as a major of the membrane component. They are derivatives of the C18 amino alcohol sphingosine. The double bond in the structure is trans.There are three types of the sphingolipids. The first one is sphingomyelins where can be found at the nerve cells and the seconds one is cerebrosides where can be found at the membrane of the brain. Cerebrosides consist only a single unit of sugar in their molecule structure. The last one is gangliosides which have 3 and more of sugar unit in their structure molecule. It’s constitute 6 % of the brain lipids.  

The fifth group of lipids is steroids. It’s has three 6 membered rings and one 5 membered rings that are fused together. Most common steroids are cholesterol. The function of the steroids is, it can act as a precursors of other steroids in animals. The function of steroids are salt balance, metabolic and sexual function.

The sixth group of the lipids is terpens. Terpens are major biosynthetic building blockswithin living creature. Terpens are derived biosynthetically from units of isoprene. Usually, we can find terpens in plant such as lavender. The function of the terpens are produce color and odor in plant to make essential oil, vitamins and precursors and  visual pigment and lastly chloroplast pigment.

The seventh of the lipids is eicosanoids. Eicosanoids are signaling molecule mades by oxidation of C20 essential fatty acids (EFAs). Eicosanoids derive from either omega-3 or omega-6. The function of the eicosanoids are for inflammation or  immunity and acts as messengers in central nervous system. 

Last group of the lipids soluble vitamin (A,D,E,K). Vitamins A we usually get it from carotenboids. Vitamin A is a group of unsaturated nutritional organic compounds. Function of vitamin A is in the visual cycle of rod cells. Vitamins D is play a role in the regulation of calcium and phosphorus metabolism. The most abundant form in the circulatory system is vitamin D3. For vitamin E, is a group of compounds of the similar structure and the most active is alpha tocopherol. Vitamin E is an antioxidant .

That’s all for today about lipids. Biochemistry class always make me gain more knowledge about new things for our daily life. 

Qila