Glucose biochem

• What is the other name for the citric acid cycle?

  Krebs cycle
• Where does the citric acid cycle occur?

  In the mitochondria
• What does the citric acid cycle oxidize?

  Acetyl moiety of acetyl-CoA
• What is produced alongside CO2 in the citric acid cycle?

  Reduced coenzymes
• Which reactions in the TCA cycle are irreversible?

  Reactions 1, 3, and 4
• What are the stages of the TCA cycle?

  • Stage I: Condensation
  • Stage II: Isomerization and oxidative decarboxylation
  • Stage III: Oxidation and hydration
• What enzyme catalyzes the condensation in Stage I?

  Citrate synthase
• What is the product of the condensation reaction in Stage I?

  Citrate
• What is the role of aconitase in the TCA cycle?

  Isomerization of citrate
• What coenzymes are required for the alpha-ketoglutarate dehydrogenase complex?

  TPP, FAD, Lipoic acid, NAD+, CoA
• What type of phosphorylation occurs with succinyl-CoA synthetase?

  Substrate level phosphorylation
• What is produced during the oxidative decarboxylation of 5C to 4C?

  CO2 and NADH
• What is the function of succinate dehydrogenase in the TCA cycle?

  Oxidation of succinate
• What regulates the TCA cycle at the allosteric level?

  Enzyme activities
• What is the role of the electron transport chain in the TCA cycle?

  Re-oxidizes coenzymes NADH and FADH2
• What is the total ATP yield from one cycle of TCA?

  30 ATP
• What is the final common pathway for the oxidation of carbohydrates, lipids, and proteins?

  The citric acid cycle
• What are the main substrates that enter the TCA cycle?

  • Carbohydrates
  • Lipids
  • Proteins
  • Fatty acids
  • Amino acids
• What does the TCA cycle generate from one molecule of acetyl-CoA?

  Two molecules of CO2
• What is the nature of the TCA cycle?

  Amphibolic
• Which cells do not perform the TCA cycle?

  Red blood cells
• What are the main functions of the TCA cycle?

  • Production of energy
  • Provide substrates for the electron transport chain
• What are the stages of reactions in the TCA cycle?

  1. Condensation of pyruvate with coenzyme-A
  2. Breaking down of the carrier
  3. Regeneration of the carrier
• What is the first reaction in the TCA cycle?

  Attachment of acetyl-CoA to oxaloacetate
• What is the last step of the TCA cycle?

  Regeneration of oxaloacetate
• What is the significance of the TCA cycle in metabolism?

  Final oxidation pathway for macromolecules
• How does the TCA cycle contribute to ATP production?

  By generating NADH and FADH2 for ETC
• What is the role of GTP in the TCA cycle?

  Converted to ATP
• How many ATP are produced from glycolysis?

  8 ATP
• What is the total ATP yield from glycolysis and TCA cycle combined?

  38 ATP
• What is the overall purpose of the TCA cycle?

  To oxidize acetyl-CoA and generate energy
• What is the main focus of Biochem 310?

  Gluconeogenesis
• What are the key features of the gluconeogenesis pathway?

  • Converts lactate to pyruvate in the liver
  • Involves the Cori cycle
  • Maintains blood glucose levels
• What is generated by muscle and transported to the liver in the Cori cycle?

  Lactate
• What happens to lactate in the liver during the Cori cycle?

  It is converted into pyruvate
• What is the other name for the glucose-alanine cycle?

  Cahill cycle
• What occurs in the muscle during the glucose-alanine cycle?

  Pyruvate is converted to alanine
• What happens to alanine in the liver during the glucose-alanine cycle?

  It is converted to pyruvate
• Why can't muscle export glucose?

  It lacks glucose-6-phosphatase
• What are the critical functions of gluconeogenesis?

  • Maintains blood glucose levels around 5.5 mM
  • Prevents hypoglycemia, which impairs brain function
  • Prevents hyperglycemia, linked to diabetes