This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification and metabolism of amino acids, Subject name: Biochemistry
All of the following amino acids forms acetyl CoA Pyruvate Dehydrogenase EXCEPT 
Select and explain. 
A. Glycine, B. Hydroxyproline, C. Tyrosine, D. Alanine
C: Tyrosine
Answer: C: Tyrosine 
Explanation: Six amino acids form pyruvate during catabolism. They are Glycine, Alanine, Serine, Threonine, Cysteine and Hydroxy-Proline (see fig).