biochem

• Lipids


  Important functional group<|>Structure of lipids

  
• Structure of lipids


  • Fatty acid
  • Glycerol
  • Phosphate group
  • Steroid nucleus
• Fatty acids


  • Saturated
  • Unsaturated
• Characteristics of fatty acids

  • Long hydrocarbon chain
  • Carboxylic acid group
• Fats and oils


  • Solid at room temperature (fats)
  • Liquid at room temperature (oils)
  • Triglycerides
  • Esters of glycerol and fatty acids

  
• Chemical properties of fats and oils

  Saponification<|>Hydrogenation
• Soaps


  Salts of fatty acids
• Hydrogenation


  1. Addition of hydrogen to unsaturated fatty acids to make them saturated

  2. Increases melting point

  3. Produces trans fats
• Waxes


  Esters of long-chain alcohols and fatty acids
• Phosphoglycerides


  Lipids containing a phosphate group
• Lecithins


  • Phosphoglycerides with a choline group
  • Found in cell membranes
  • Emulsifiers
• Cephalins


  Phosphoglycerides without a choline group
• Glycolipids


  • Sphingolipids with a carbohydrate group
  • Found in cell membranes
• Biological membranes


  • Contain lipids and proteins
  • Selectively permeable
  • Fluid mosaic model

  
• Fluid mosaic model


  Model of biological membrane structure with lipids and proteins in a fluid, dynamic arrangement

  
• Steroids


  Lipids with a characteristic four-ring structure
• Cholesterol


  Steroid found in cell membranes and used to synthesize other steroids
• Bile salts


  • Cholesterol derivatives
  • Emulsify fats
• Gallstones can form from excess cholesterol
• Sex hormones


  Steroid hormones involved in sexual development and function