Fats/lipids

• Structure of a phospholipid

  Has a phosphate group

  fatty acid tails which are non-polar and hydrophobic

  phosphate heads which are polar and hydrophyllic
• Saturated fats 


  no c=c bonds present, carbon is forming as many bonds with hydrogen as possible.
• Unsaturated fats


  Atleast one c=c double bond
• Mono and poly refers to the number of double bonds present
• Hydrogenation 


  Adding hydrogen to an unsaturated fatty acid to replace double bonds with hydrogen molecules to straighten the chain
• This image shows the formation of fatty acids as well as the process of hydrogenation through fatty acids

  
• Hydrolysis


  Breaking a bond using water
• Condensation reaction


  Forming a bond and obtaining water
• These diagrams show examples of hydrolysis and condensation reactions and also the formation of triglycerides lipids

  
• Formation of phospholipids and arrangements

  
• Cholesterol 


  Whether synthesised in the body of consumed in the body, cholesterol is required to make steriod based hormones and cell membranes

  e.g. oestrogen, progesteron and testosterone
• Mechanism of steroid hormones 


  -steroid hormones must be bound to a protein carrier in the blood as they are non-polar

  -can freely diffuse through phospholipid bilayer as both are non polar (hormone and fatty acid tail)

  -binds to a receptor protein, this complex moves into the nulceus and binds to genes

  -receptor hormone complex increases transcription and translation of specific genes resulting on more protein synthesis and up regulates gene expression

  -resulting in more protein, more characteristics