Summary
Highlights
The Krebs cycle is where acetyl-CoA, derived from glucose, is completely oxidized into carbon dioxide. This marks the complete breakdown of the original glucose molecule.
Acetyl-CoA reacts with a four-carbon molecule, oxaloacetate, to form a six-carbon molecule called citric acid. This is why the Krebs Cycle is also known as the Citric Acid Cycle.
Citric acid undergoes oxidation, transferring electrons and hydrogens to NAD+ to form NADH and releasing CO2, resulting in a five-carbon molecule. This molecule is further oxidized, producing another NADH and CO2, yielding a four-carbon molecule.
The four-carbon molecule undergoes a reaction that generates ATP by joining ADP and phosphate.
The molecule is further oxidized, transferring electrons and hydrogens to FAD, creating FADH2. This new four-carbon molecule is then oxidized one more time, producing more NADH and regenerating oxaloacetate, completing the cycle.
The Krebs cycle produces numerous electron carriers (NADH and FADH2) for the electron transport chain, ATP for energy, and carbon dioxide as a waste product.
The video recaps the cyclical nature of the Krebs cycle and encourages viewers to use the Bioman Biology interactive activity to practice their understanding of the process.