How do the electrons removed from glucose during glycolysis and the Krebs cycle contribute to the formation of ATP?

The electrons are removed from glucose during the sixth stage of glycolysis. In glycolysis, the electrons are extracted from glyceraldehyde-3-phosphate which is a 3 carbon sugar molecule. This electron is transported by electron carriers called NAD+.

The main contribution of Krebs cycle is the formation of electron carriers which is required in the process of respiration.