Topic 10 Lipids I

Lipids perform a variety of basic functions within the body (see figure 10.1), including but not limited to:

Functions of Lipids

Figure 10.1: Functions of Lipids

  1. Storing fat and providing energy

    Fats can provide up to 9 kcal per kilogram; carbohydrates can only yield up to 4 kcal per kilogram!

  2. Provide insulation

  3. Help manufacture steroids and bile salts

  4. Signalling

  5. Play a role in transporting fat-soluble nutrients in blood

  6. Manufacturing sex hormones (i.e., estrogen and testosterone)

  7. Cell membrane synthesis

    Types of Membrane Lipids

    Figure 10.2: Types of Membrane Lipids

    Figure 10.2 shows the five general types of membrane liipds:

    1. Glycerophospholipids
    2. Sphingolipids
    3. Galactolipids and sulfolipids
    4. Archaebacteria tetraether lipids
    5. Sterols (i.e., compounds with a rigid system of four fused hydrocarbon rings)

Furthermore, several diseases are also attributed with the abnormal chemistry or metabolism of lipids:

  1. Obesity
  2. Artherosclerosis
  3. Hypolipoporteinemia
  4. Hyperlipoporteinemia
  5. Steatosis (i.e., fatty liver)
  6. Lipidosis (i.e., lipid storage diseases)