The Krebs Cycle Explained (Aerobic Respiration)

Introduction to the Krebs Cycle00:00:00

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.

Formation of Citric Acid00:00:25

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.

Oxidation and CO2 Release00:00:39

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.

ATP Production00:01:04

The four-carbon molecule undergoes a reaction that generates ATP by joining ADP and phosphate.

FADH2 and NADH Production00:01:18

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.

Outputs of the Krebs Cycle00:01:51

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.

Recap and Interactive Activity00:02:19

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.