ISB 201 Lecture 5: ISB 201 E

About 10% of the glucose residues released from glycogen breakdown yield only 2 ATP/glucose molecule instead of the 3 ATP when you are vigorously exercising, and your muscle cells are being powered by glucose supplied from the degradation of their glycogen stores. Explain why approximately one of every 10 glucose units released from glycogen only gives us 2 ATP/glucose. Think about the structure of glycogen.

When you are vigorously exercising, and your muscle cells are being powered by glucose supplied from the degradation of their glycogen stores, you will produce 3 ATP glucose molecule during glycolysis instead of the normal yield of 2 ATP/glucose during glycolysis.

Explain why the higher yield is only a short-term gain and why, in the long-term, you aren't really getting an extra ATP/glucose.