Fatty acid
Malonyl-CoA is then involved in a repeating series of reactions that lengthens the growing fatty acid chain by two carbons at a time. Almost all natural fatty acids, therefore, have even numbers of carbon atoms. When synthesis is complete the free fatty acids are nearly always combined with glycerol (three fatty acids to one glycerol molecule) to form triglycerides, the main storage form of fatty acids, and thus of energy in animals. However, fatty acids are also important components of the phospholipids that form the phospholipid bilayers out of which all the membranes of the cell are constructed (the cell wall, and the membranes that enclose all the organelles within the cells, such as the nucleus, the mitochondria, endoplasmic reticulum, and the Golgi apparatus).
Essential fatty acid
Reference intake values for as published by the Panel on Dietetic Products, Nutrition and Allergies of the European Food Safety Authority (EFSA).
In the United States, the recommendations for omega-3 fatty acids covers ALA, EPA and DHA, and for adults the values are 1.6 g/day for men and 1.1. g/day for women. The recommendation for omega-6 fatty acids is for linoleic acid: 17 g/day for younger men, dropping to 14 g/day for older men; for women 12 and 11 g/day.