Polyunsaturated fats have more than one double bond. The double bonds are always 3 carbons apart from each other. At each double bond the carbon chain has a permanent bend in it, so that if four double bonds are present, the tail nearly reaches back to the head. We will find later that the unsaturated fats in cells membranes are often broken down and used for messenger molecules either in cells or between cells. Lipids are organic molecules that dissolve in organic solvents.
Fats are molecules that have a fatty acid moiety.
Most fatty acids are found in triglycerides or phospholipids. Phospholipids have glycerol, a phosphate group or an organic phosphate group, and two fatty acid moieties. Unfortunately most flavors are found in fats. Starches and sugars, carbohydrates , are all treated in the same manner by the body. They are essential for normal metabolism and should make up the bulk of the diet.