This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory Chain, Subject name: Biochemistry
Substrate level phosphorylation is catalysed by : 
Select and explain. 
A. Succinate dehydrogenase, B. Thiokinase, C. Malate dehydrogenase, D. Hexokinase
B: Thiokinase
Answer: B: Thiokinase 
Explanation: Ans is 'b' i.e. Thiokinase/7te/i Chatterjee Shinde, 4/e, p 264]* There are two types of phosphorylation of ADP to ATP: -Oxidative phosphorylation at the respiratory chain levelSubstrate level phosphorylation.Substrate level phosphorylation :Is production of ATP 'at the substrate level' without the participation of the electron transport chain.Examples of substrate level phosphorylation :2 in glycolytic pathway &1 in Citric acid (TCA) cycle.