Lipids
What are Lipids?
A Lipid is a large and varied group of naturally occurring molecules that are not generally soluable in water. The main functions of lipids include storing energy, providing structural components to cell membrane, and as important signaling molecules. Because lipids aren't soluable in water, the bonds cannot be broken by hydrolysis. This is why sugars are better gaining energy than eating something that is a lipid. The three main types of lipids are fats, waxes, and oils. There are many others including monoglycerides, diglycerides, triglycerides, and phospholipids. Lipids are made up of carbon, hydrogen, and oxygen atoms. The structural make up determines the type of lipid. Lipids are usually very complex. The monomers of a lipid contain glycerol. They also contain three fatty acids known as triglycerides. Fat is found in animals, whereas oil is found in plants. Fat is the solid form of oil which is the liquid form of fat. The state depends on the room temperature. Most fats are hydrophobic meaning they have a long chain of hydrocarbons. The tail of a fat is a carboxyl group containing oxygen as well as hydrogen and carbon.
Vegetable oil is an example of a lipid.
This is a diagram of the sturcture of a fat (saturate lipid) and a oil (unsaturated oil). You can see the difference in the extra length of hydrocarbons coming of the double bonded carbon on the tail.