gluconeogenesis

• Gluconeogenesis


  The process of producing glucose from non-carbohydrate sources
• Gluconeogenesis


  • Produces glucose from lactate, amino acids, and glycerol from triglycerides
  • Triggered by low blood glucose levels
  • Outcome is increased blood glucose levels
• Glycolysis


  The process of converting glucose into pyruvate
• Pyruvate


  Can be converted to lactate under anaerobic conditions
• Lactate


  Can be used as a substrate for gluconeogenesis in the liver
• Gluconeogenesis from lactate


  1. Lactate enters liver cell and is converted to pyruvate

  2. Pyruvate enters mitochondria and is converted to oxaloacetate

  3. Oxaloacetate is converted to malate which exits mitochondria

  4. Malate is converted back to oxaloacetate

  5. Oxaloacetate enters gluconeogenic pathway

  6. Fructose 1,6-bisphosphatase enzyme helps reverse glycolysis

  7. Glucose 6-phosphate is converted to glucose by glucose-6-phosphatase and exits the cell
• Glycerol


  From triglycerides can also be used as a substrate for gluconeogenesis
• Amino acids


  Alanine can be used as substrates for gluconeogenesis
• Acetyl-CoA


  Cannot be converted to glucose, but can be used to produce ketones
• Diabetes


  Excessive breakdown of triglycerides and amino acids for gluconeogenesis can lead to ketoacidosis
• Hormones that stimulate gluconeogenesis

  • Glucagon
  • Cortisol
  • Noradrenaline
• Fatty acids enter the mitochondria and convert into acetyl coA -> produces ketones _
• Ketone bodies are produced from fatty acid oxidation in the liver.