ALTERNATIVE RESPIRATORY SUBSTRATES

• ALTERNATIVE RESPIRATORY SUBSTRATES?

  lipids and proteins
• RESPIRATION OF LIPIDS?

  1. Lipids hydrolysed into glycerol and fatty acids
  2. Glycerol phosphorylated
  3. Enters glycolysis and later Krebs Cycle
  4. Fatty acids broken down into 2C fragments
  5. Then converted into acetylCoA
  6. Enters Krebs Cycle
• HOW MUCH ENERGY IS RELEASED BY LIPIDS COMPARED TO CARBOHYDRATES?

  more than double energy at same mass
• WHY DO LIPIDS RELEASE MORE ENERGY THAN CARBOHYDRATES?

  oxidation of lipids produces 2C fragments of carbohydrates and many hydrogen atoms

  -> used to produce ATP in oxidative phosphorylation
• RESPIRATION OF PROTEINS?

  1. Hydrolysed into AAs
  2. Amino group removed (deamination)
  3. Enter respiratory pathway depending on number of carbon atoms
• WHERE DO 3C GROUPS ENTER RESPIRATORY PATHWAY?

  as pyruvate
• WHERE DO 4C/5C GROUPS ENTER RESPIRATORY PATHWAY?

  as intermediates in the Krebs Cycle