5.2.3 Krebs Cycle

• Krebs Cycle = produces NADH, FADH, ATP and 2 molecules of CO2 from acetyl CoA and a 4 carbon molecule; occurs in the matrix
• Steps of Krebs Cycle

  1. Acetylcoenzyme A (2 C) combines with a 4 C molecule to form a 6 C molecule
  2. The 6 C molecule loses 2 CO2 and 2 hydrogen to give a 4 C molecule and ATP due to substrate level phosphorylation
  3. The 4 C molecule combines with a new molecule of acetylcoenzyme A to begin the cycle again

  
• Importance of Krebs Cycle (+ Link Reaction)

  • Breaks down pyruvate into CO2
  • Produces Hydrogen atoms, used to produce NADH/FADH
  • Regenerates 4 C molecule which prevents acetyl coA from accumulate by combining with it
  • Source of intermediate compounds used by cells to manufacture amino acids, fatty acids and chlorophyll
• Importance of NADH/FADH

  • Carries H to ETC, which provides energy for oxidative phosphorylation, leading to the production of ATP