in what cycle does substrate-level phosphorylation occur?
Glycolysis and oxidative phosphorylation is two, and then there is also the citric acid cyle (also caled the Kreb's cycle). Substrate-level phopshorylation happens in both glycolysis and the Kreb's cycle. The only difference is that the Kreb cycle is also in the mitochondria and glycolysis is not (it's in the cytoplasm).