Skip to main content
Medicine LibreTexts

2.3: Lipids

  • Page ID
  • Lipids, commonly referred to as fats, have a poor reputation among some people, in that "fat free" is often synonymous with healthy. We do need to consume certain fats and we should try to incorporate some fats into our diets for their health benefits. However, consumption of certain fats is also associated with greater risk of developing chronic disease(s). In this section we will dive deeper into fats and why they do not need to be feared altogether.

    • 2.3A: How Does Fat Differ From Lipids?
      Fats are solid at room temperature, while oils are liquid at room temperature. However, from a caloric perspective, an oil is a fat. For example, let's consider olive oil. Clearly, it is an oil according to a chemist definition, but from a caloric standpoint it is a fat because it provides 9 kcal/g.
    • 2.3B: Fatty Acids
      Fatty acids are lipids themselves, and they are also components of triglycerides and phospholipids. Like carbohydrates, fatty acids are made up of carbon (C), hydrogen (H), and oxygen (O).
    • 2.3C: Fatty Acid Naming and Food Sources
      There are three naming systems used for fatty acids: (1) Delta nomenclature, (2) Omega nomenclature, and (3) Common names The omega nomenclature and common names are used more in the field of nutrition than the delta nomenclature when describing specific fatty acids.
    • 2.3D: Essential Fatty Acids and Eicosanoids
      The two essential fatty acids are: (1) linoleic acid (omega-6) and (2) alpha-linolenic (omega-3). These fatty acids are essential because we can not synthesize them.
    • 2.3E: Triglycerides
      Triglycerides are the most common lipid in our bodies and in the foods we consume. Fatty acids are not typically found free in nature, instead they are found in triglycerides. Breaking down the name triglyceride tells a lot about their structure. "Tri" refers to the three fatty acids, "glyceride" refers to the glycerol backbone that the three fatty acids are bonded to.
    • 2.3F: Phospholipids
      Phospholipids are similar in structure to triglycerides, with the only difference being a phosphate group and nitrogen-containing compound in the place of a fatty acid.
    • 2.3G: Sterols
      The last category of lipids are the sterols. Their structure is quite different from the other lipids because sterols are made up of a number of carbon rings.

    Contributors and Attributions

    • Was this article helpful?