ATP is synthesized by substrate-level phosphorylation during which of the following? a) conversion of pyruvate to lactate only b) glycolysis only c) glycolysis, the Krebs cycle, and during conversion of pyruvate to lactate d) Krebs cycle only e) glycolysis and the Krebs cycle only Also, just for my own knowledge, Is conversion of pyruvate to lactate considered substrate level phosphorylation? Thanks.