This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
Gluconeogenesis enzyme stimulated in starvation 
Select and explain. 
A. Carboxylase, B. Pyruvate dehydrogenase, C. Pyruvate kinase, D. Glucokinase
A: Carboxylase
Answer: A: Carboxylase 
Explanation: In starvation, there is excessive breakdown of fatty acids resulting in the formation of Acetyl CoA in the liver. They ensure the conversion of pyruvate to oxaloacetic acid. It acts as allosteric activator of the enzyme pyruvate carboxylase and inhibits pyruvate dehydrogenase of Glycolysis.