MCAT Basics (from MedSchoolCoach) The Krebs Cycle
Jun 26, 2025
In this discussion, guest host Alex Starks, a skilled educator in metabolic processes, breaks down the Krebs cycle's significance for the MCAT. He explains how pyruvate transforms into acetyl CoA and details each step of the cycle, from citrate formation to GTP production. Alex highlights the importance of thioester bonds and how the cycle connects to blood pH through CO2 production. He also differentiates between key enzymes and explores the cycle's regulation, providing valuable insights for aspiring medical students.
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PDC Links Glycolysis To The TCA
- The pyruvate dehydrogenase complex converts cytosolic pyruvate into mitochondrial acetyl-CoA while producing CO2 and NADH.
- This links glycolysis to the TCA cycle and supplies electrons to the electron transport chain.
Track Structures And Carbon Flow
- Visualize molecular structures and track carbon changes to understand each TCA step.
- Focus on how acetyl-CoA's thioester hydrolysis powers citrate formation and subsequent oxidation.
Thioester Cleavage Drives Citrate Formation
- Citrate synthase catalyzes an irreversible condensation of acetyl-CoA with oxaloacetate to form citrate.
- The reaction is driven by hydrolysis of a high-energy thioester bond in acetyl-CoA.