Lipids

Cards (32)

  • lipids are another important class of nutrients that include fatty acids, phospholipids, steroids, and cholesterol
  • primary functions will be discussed further in lipid classifications
    • source of energy
    • Energy storage
    • Cell membrane component
    • Protection and insulation
    • Digestion and absorption
  • fatty acids consist of a long hydrophobic, non-polar hydrocarbon “tail”, and a hydrophilic polar carboxylic acid functional group at the “head”
  • natural fatty acids may be classified as
    • saturated fatty acids
    • unsaturated fatty acids
  • saturated fatty acids have no carbon-carbon double bonds
  • unsaturated fatty acids contain one or more double bonds in the hydrocarbon chain
  • lauric acid - a saturated fatty acid found in coconut oil
  • Oleic acid - an unsaturated fatty acid found in animal fat
  • essential fatty acids
    • Linoleic acid
    • Linolenic acid
  • Essential fatty acids are precursor in the sentences of prostaglandins. A group of lipids greatly affects a number of important physiological process.
  • trans fats or trans fatty acids can be formed through a process called hydrogenation, which makes the oil more solid
  • the cis and trans configurations influence the shape of fatty acid molecules
  • trans configuration that twist or kink produced by the double bond in the cis configuration is not observed
  • trans fats can be found in many food products such as
    • Cookies
    • Cakes
    • Savory snacks
  • classification of lipids
    • simple lipids
    • Complex lipids
  • steroids are simply lipids that have a backbone structure, consisting of four fused carbon rings
  • cholesterol is the most abundant steroid in animal tissues. It is composed of steroid backbone structure with hydroxyl group at one end and a branched hydrocarbon chain at the other.
  • cholesterol serves us
    • Base of other steroids
    • Male and female hormones
    • Vitamin D
    • Bile acid
  • The most abundant class of lipids in plants and animals is that triglycerides
  • triglycerides are composed of
    • Three fatty acids
    • Single glycerol
  • esterification is the reaction between an alcohol and a carboxylic acid that produces an ester and water
  • Triglycerides are the major lipids found in the blood
  • at room temperature, solid triglycerides usually of animal origin are called fats
  • liquid triglycerides, usually from plants are called oils
  • phospholipids are the fundamental building blocks of cellular membranes
  • phospholipids are have two distinct parts
    • Hydrophilic phosphate head
    • Long hydrophobic tail
  • lecithin is an example of phospholipid. It is a major component of cell membrane and this use as an modifying agent
  • lecithin is naturally found in
    • Egg yolks
    • nut
    • Whole grains
    • Soybeans
  • another phospholipid is cephalin, which is found in the cell membranes of the brain and tissue and in blood platelets
  • waxes are water-insoluble, low-melting solids that consist of a long chain fatty acid and a long chain, monohydroxy alcohol
  • Types of waxes
    • Beeswax
    • Chinese wax
    • Earwax
    • lanolin
    • shellac
    • Spermaceti
    • Vegetable wax
  • Phospholipids are made up of two fatty acids, glycerol, phosphate, and one simple organic molecule