It is said that 1 ATP is produced in the Krebs cycle; I can't seen to find it though. Where is it produced?
One GTP is formed by substrate level phosphorylation in the coupled reaction forming succinate from alpha-keto-glutaric acid. This GTP is energetically equivalent to ATP, and there is an enzyme in the cell that will carry out the interconversion: GTP + ADP <--> GDP + ATP, Delta Go = ~0.