In the citric acid cycle, all the intermediates (e.g. citrate, iso-citrate, alpha-ketoglutarate, succinate, fumarate, malate and oxaloacetate) are regenerated during each turn of the cycle. Adding more of any of these intermediates to the mitochondrion therefore means that the additional amount is retained within the cycle, increasing all the other intermediates as one is converted into the other. Hence, the addition of any one of them to the cycle has an anaplerotic effect, and its removal has a cataplerotic effect. These anaplerotic and cataplerotic reactions will, during the course of the cycle, increase or decrease the amount of oxaloacetate available to combine with acetyl-CoA to form citric acid. This in turn increases or decreases the rate of ATP production by the mitochondrion, and thus the availability of ATP to the cell.
In the citric acid cycle all the intermediates (eg citrate iso-citrate alpha-ketoglutarate succinate fumarate malate and oxaloacetate) are regenerated during each turn of the cycle Adding more of any of these intermediates to the mitochondrion therefore means that the additional amount is retained within the cycle increasing all the other intermediates as one is converted into the other Hence the addition of any one of them to the cycle has an anaplerotic effect and its removal has a cataplerotic effect These anaplerotic and cataplerotic reactions will during the course of the cycle increase or decrease the amount of oxaloacetate available to combine with acetyl-CoA to form citric acid This in turn increases or decreases the rate of ATP production by the mitochondrion and thus the availability of ATP to the cell