This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Phenylalanine and Tyrosine metabolism Detail, Subject name: Biochemistry
Phenylalanine is degraded into 
Select and explain. 
A. Fumarate and succinate, B. Fumarate and acetoacetate, C. Fumarate and Malate, D. Fumarate and pyruvate
B: Fumarate and acetoacetate
Answer: B: Fumarate and acetoacetate 
Explanation: Phenylalanine is first conveed to tyrosine (For Subsequent metabolism of phenylalanine and tyrosine See att. Treasure. Hereditary tyrosinemia type I (Hepatorenal tyrosinemia) is due to deficiency of the enzyme fumaryl acetoacetate hydrolase (fumarylacetoacetase). Remember the enzyme deficiency - fumarylacetoacetase. That will help you to remember the end products - Fumarate and acetoacetate. Phenylalanine & tyrosine are both glucogenic and ketogenic. Fumarate is glucogenic while acetoacetate is ketogenic.