Multiple choice Substrate phosphorylation occurs when Citric Acid changes into Cis Aconotic acid Malic acid changes into Oxalo Acetic Acid Fumaric acid changes into Malic Acid Succinyl Co A changes into Succinic Acid Reveal answer Fill a bubble to check yourself D Correct answer Explanation Substrate-level phosphorylation occurs when a high-energy phosphate bond is transferred directly to ADP or GDP. The conversion of Succinyl-CoA to Succinic acid by Succinyl-CoA synthetase is a classic example of this.