The number of substrate level phosphorylations in one turn of citric acid cycle is :

There is only one substrate level phosphorylation in one turn of citric acid cycle during conversion of succinyl CoA to succinic acid. There is  a molecule of GTP is synthesized during this conversion. During the aerobic respiration of one molecule of  glucose, the TCA cycle is repeated twice and the total number of substrate level phosphorylation is then two.