BIOMED SCIE Lecture 7 Cardiovascular Disease II

• Platelets


  • Flowing disc-shaped
  • Rolling ball-shaped
  • Hemisphere-shaped
  • Spreading
• Blood clotting: Normal Haemostasis


  • Well-regulated process
  • Maintains blood in a fluid, clot-free state in normal vessels
  • Induces the rapid formation of a localised haemostatic plug at the site of vascular injury
• Thrombosis


  • Pathological state
  • Inappropriate activation of the normal haemostatic process within the non-interrupted vascular system
  • Thrombus (blood clots) formation that blocks blood flow to vital areas
• Basic Biomolecules in Biochemistry

  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
• Monomers (Building Blocks)


  • Monosaccharide
  • Fatty acids
  • Amino acids
  • Nucleotides

  
• A diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits
• Trans fats may contribute more than saturated fats to cardiovascular disease
• Omega-3 fatty acids promote a healthy heart
• Lipids


  • Very diverse group
  • Naturally-occurring
  • All are non-polar – water 'hating'/water insoluble
• Types of Lipids


  • Simple Lipids: Fats, oils & waxes
  • Complex lipids: Simple lipids but with other stuff attached
  • Steroids: fused ring compounds e.g., cholesterol, oestrogen, testosterone
  • Other: Fat soluble vitamins (such as Vit A, D, E and K)

  
• Biologically Important Lipids


  • Serve as structural components of biological membranes
  • Provide energy reserves, predominantly in the form of triacylglycerols (glycerol + 3 fatty acids)
  • Both lipids and lipid derivatives serve as vitamins and hormones
  • Lipophilic bile acids aid in lipid solubilisation
  • Insulation
• Triglycerides


  • Fats & oils
  • Made up of Fatty acids combined with glycerol

  
• Fatty Acids


  • Polar end – carboxylic acid group (hydrophilic)
  • Non-polar tail – hydrocarbon chain (hydrophobic)
  • May be monounsaturated, polyunsaturated, or saturated

  
• Saturated Fatty Acids


  • Contain no carbon double bonds

  
• Unsaturated Fatty Acids


  • Contain a double bond
  • Monounsaturated - one double bond
  • Polyunsaturated - Multiple C=C bonds

  
• Unsaturated fatty acids


  Lower melting point (due to 'kinks'!)
• Saturated Fats


  Fats made from saturated fatty acids, solid at room temperature, mostly from animal sources
• Unsaturated Fats/Oils

  Fats made from unsaturated fatty acids, liquid at room temperature, mostly from plant and fish sources
• Butter contains mainly saturated fatty acids and cholesterol
• Margarine is traditionally made from partially hydrogenated vegetable oil to make it more solid at room temperature

  
• Olive Oil is made up of unsaturated fatty acids, with oleic acid being the main component
• Essential Fatty Acids (EFA's)


  Polyunsaturated FA's not synthesised by the body but needed for normal metabolism, must be supplied in the diet

  
• Essential Fatty Acids


  • Linoleic acid (major dietary Omega-6 fatty acid)
  • Linolenic acid (major dietary Omega-3 fatty acid)
  • Eicosapentaenoic acid (EPA) (longer-chain omega-3 fatty acid)
  • Docosahexaenoic acid (DHA) (longer-chain omega-3 fatty acid)

  
• Omega-3 and omega-6 are not interconvertible in the body
• Optimum balance of omega-3 to omega-6 is 1:4, but Western diet can be up to 1:25
• Omega-3 fatty acids have anti-inflammatory effects, while omega-6 fatty acids have inflammatory effects
• Increased levels of omega-3 shown to have a role in the prevention of cardiovascular diseases, stress, ADHD, depression and Alzheimer's disease
• Omega-3 fatty acids promote healthy heart, brain function, lower blood pressure and have many other benefits
• Pharmaceutical companies are harnessing the therapeutic potential of polyunsaturated fatty acids (such as omega-3)
• The most biologically important lipids are fats, phospholipids and steroids
• Glycerol is a three-carbon alcohol with a hydroxyl group attached to each carbon
• A fatty acid consists of a carboxyl group attached to a long carbon skeleton
• Acid + alcohol – water = ester
• Fatty acids are esterified with glycerol (trihydroxy alcohol) to form triacylglycerols
• The greater the number of double bonds the lower the melting point
• Why some fatty acids are essential?


  Important components in all cell membranes, particularly brain neurons (Omega-3). Involved in energy metabolism. They are building blocks for hormones that control immune function, blood clotting and cell growth