Cori Cycle & Glucose-Alanine Cycle
Start with the big picture
During anaerobic glycolysis, muscle converts pyruvate to lactate, producing 2 ATP per glucose. The Cori cycle carries lactate to the liver, where it is converted back to glucose at a cost of 6 ATP equivalents; the glucose can then return to muscle. In the glucose-alanine cycle, muscle transfers nitrogen to pyruvate to form alanine. The liver uses alanine’s carbon skeleton to make glucose and sends its nitrogen into the urea cycle. This cycle therefore supports glucose supply while helping remove nitrogen from muscle, but its hepatic energy cost is higher than that of the Cori cycle. The lesson also compares regulation, physiological functions, key enzymes, and clinical relevance for both pathways.
What you'll learn
- Trace lactate and glucose through the Cori cycle between muscle and liver.
- Describe how alanine carries carbon and nitrogen from muscle to liver.
- Compare the ATP costs and physiological roles of the two cycles.
- Identify key enzymes and hormonal regulators in each pathway.
- Recognize clinical contexts associated with altered cycling.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
