LIPIDS

• Lipids


  Substances that include fats and fat-like substances such as phospholipids, waxes, steroids, and others
• Lipids come from the Greek word Lipos which means "fat"
• Lipids


  • Mainly consist of carbon, hydrogen, and oxygen
• Main functions of lipids

  • Store and produce energy
  • Serve as insulating materials to prevent heat loss and protection against extreme cold
  • Serve as a solvent for fat-soluble vitamins and hormones
  • Prevent water loss in the skin
• Insoluble forms of lipids

  • Ether
  • Chlorofirm
• Lipids composition


  One molecule of glycerol and three fatty acids molecules connected by ester bonds
• Types of fatty acids

  • Saturated
  • Unsaturated
• Saturated fatty acids


  • Solid at room temperature
  • Mostly found in animals
  • No double bonds
• Unsaturated fatty acids


  • Liquid at room temperature
  • Mostly found in plants
  • Believed to be healthier than saturated
• Monounsaturated fatty acids


  • Palmitoletic acid
  • Oleic acid
• Unsaturated omega-6 fatty acid


  • Linoleic acid
• Trans fat


  • Unsaturated fat with trans isomer fatty acid(s) containing one or more double bonds between the carbon atoms
  • Not essential for the body's function
  • Do not promote good health
• Cis fat


  Two hydrogen atoms adjacent to a double bond are on the same side
• Omega-3 fatty acid


  • Family of unsaturated fatty acids with a final carbon-carbon double bond in the n-3 position
  • Health benefits include cancer prevention, cardiovascular disease prevention, immune function, and brain health
• Waxes


  • Solid at room temperature due to high melting point
  • Hydrophobic
  • Provide a protective cuticle that retards water loss in plants
  • Involved in skin and fur maintenance in animals
  • Produced by glands in the outer ear canal in humans
• Triglycerides


  • Function for long-term energy storage
  • Contain three fatty acids attached to each glycerol molecule
  • Immiscible with water
• Phospholipids


  • Major component of all cell membranes
  • Can form lipid bilayers
• Phospholipids


  • Most contain two fatty acid molecules and one phosphate group
• Sphingolipids


  • Specifically found in the brain, lungs, and nerve tissues
  • Essential in signal transmission and cell recognition
• Steroids


  • Lipids with a carbon skeleton of four fused rings
  • Examples include cholesterol, sex hormones, and anti-inflammatory drugs
• Lipids play a diverse role in biological functions
• Oils and fats are predominantly used for energy storage
• Fatty or adipose tissues in animals function as insulation below the skin to protect from low temperatures