Structure of a Triglyceride

Triglycerides are lipids, a form of large organic molecule essential for the functioning of living organisms. Triglycerides are commonly known as fats, and like all organic molecules, are based at the chemical level on the carbon atom. The type and number of bonds carbon forms in the triglyceride affects the properties of the fat and how it functions in the body. Fat substitutes function differently in the body than natural fats due to their chemical properties.

Facts

• "Triglyceride" is another name for an animal or vegetable oil fat. Fats are called triglycerides because of the chemical structure of their molecules. A triglyceride consists of a glycerol molecule (a three-carbon alcohol) joined to three fatty acid "tail" molecules. Triglycerides may be liquid (oil) or solid (butter or lard) at room temperature. In the body fats function as energy storage and are produced by a cellular organelle called the endoplasmic reticulum.

Saturated Fats

• Most of us have heard that saturated fats are less healthy than unsaturated fats. The reason has to do with differences in the chemical structure of these molecules. In a saturated fat, carbon atoms in the three fatty acid tails form single bonds with hydrogen atoms. These carbon atoms are said to be fully "saturated," and this state makes the molecules in the tail lie straight, so that they can be tightly packed into a relatively small space. It can also allow them to pack together into arterial blockages in the body. Saturated fats tend to be solid at room temperature and come mostly from animal sources.

Unsaturated Fats

• In an unsaturated fat, some carbon atoms in the fatty acid tails form double bonds with other atoms. Because these carbon atoms are not fully "saturated," the tails form "kinks." Kinks prevent tight packing of the triglyceride molecules, which is why unsaturated fats are liquid at room temperature. Unsaturated fats are largely derived from plant sources.

Fat Substitutes

• Olestra and other artificial fats differ from natural fats in that they are designed to be difficult for the body to digest. Olestra is not a triglyceride, but instead consists of polyglycerol fatty acid esters derived from sucrose, which is a carbohydrate. These molecules are too large to be broken down by the body and instead pass through the body unchanged. Although they are not calorie-free, these molecules allow manufacturers to label products as "fat-free." However, fat substitutes may interfere with the body's ability to absorb certain vitamins, according to scientificpsychic.com.

Considerations

• Along with cholesterol, triglyceride levels are checked as part of routine blood tests during physicals. Normal triglyceride levels in the blood are about 150, according to the National Institutes of Health. Levels above 200 are considered high. High triglyceride levels can contribute to hardening of the arteries and increase the risk of heart disease and stroke.