Question

Describe the differences and similarities between lecithin and cephalin. Match the words in the left column to the appropriate blanks in the sentences on the right. ResetHelp Lecithins and cephalins are both sphingolipids; they consist of glycerol with fatty acids forming bonds with the first and second groups. The third group of the forms a with phosphoric acid, which forms another bond with an amino alcohol. In lecithins, the amino alcohol is ; in cephalins, the amino alcohol is usually .

Answer 1

Answer:

Here, we have a composition passage and we are required to fill in the with missing words. The missing words are highlighted in bold format and underlined.

Lecithins and cephalins are both glycerophospholipids; they consist of glycerol with fatty acids forming ester bonds with the first and second hydroxyl groups. The third hydroxyl group of the glycerol forms a phosphate bond with phosphoric acid, which forms another phosphate bond with an amino alcohol. In lecithins, the amino alcohol is choline; in cephalins, the amino alcohol is usually ethanolamine.

Explanation:

Lecithin is a chemical complex composed primarily of fatty acids, glycerol, phosphoric acid, and choline. It can be present in egg yolks, soybeans, sunflower seeds, and plant seed cells and is completely normal. Soybean and sunflower lecithins contain much more important fatty acids than rapeseed lecithin, making them nutritionally more useful.

Phosphatidylethanolamine, also known as cephalin, is a phosphoglyceride that, like phosphatidylcholines and lecithins, is a component of biological membranes. A glycerol residue esterified by two fatty acids and a phosphoethanolamine residue gives rise to phosphatidylethanolamines. They're made by combining CDP-ethanolamine with diglycerides and releasing a CMP molecule. Phosphatidylcholines are formed when S-adenosylmethionine methylates the amine in ethanolamines. They're mostly found in the inner layer of plasma membranes' lipid bilayers.