Lipids

Lipids are one of the main BIMS groups. They include fats, which are made from glycerol and fatty acids. Fats have many important functions in your body, like long-term energy storage, insulation, protection for bones and organs, and dissolving vitamins. Fats are also called triglycerides because they are made up of three fatty acid tails linked to one glycerol molecule. When a fat has less than the maximum amount of hydrogens, double bonds form in the fatty acid tails which make them kinked. Fats with kinked fatty acid tails are called unsaturated fats because the kinks prevent them from packing tightly together and becoming solid at room temperature. Saturated fats are solid because they have straight fatty acid tails so they can pack together. Unsaturated fats, like vegetable oil, are better for you than saturated fats, like butter, because saturated fats can contribute to heart disease. Another important lipid is a phospholipid. In a phospholipid, one of the fatty acid tails is replaced by a phosphate group. The phosphate and glycerol portion is polar, and the fatty acid part is nonpolar. This means that part of it dissolves in water and part of it does not. Because of this, phospholipids are very important in cell membranes.