respiratory substrates

• Triglycerides:

  • stored in adipose tissue
  • glycerol -> pyruvate -> acetyl
  • fatty acids are converted to acetyl
  • single fatty acid can result into 50 acetyl groups = 500 ATP
• lipids stores release twice as much energy as carbohydrates by mass
• Amino acids:

  • converted to pyruvate in liver via deaminiation
  • conversion of amino acids does required ATP so overall yield of ATP from proteins is less than carbohydrates
• Lactate -> pyruvate in anaerobic respiration
• Ketone bodies:

  • produced in the liver from fatty acids
  • can be used by the brain to produce acetyl when glucose levels are low
• Respiratory quotent = CO2 produced/O2 consumed

  • normal = 0.8-0.9
  • glucose = 1
  • proteins = 0.9
  • lipids = 0.7
  • anaerobic respiration >1
• what is a respiratory substrate?

  an organic substance that be oxidised by respiration releasing energy to make ATP