This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amino Acids Basics, Subject name: Biochemistry
Tryptophan is- 
Select and explain. 
A. Glucogenic, B. Ketogenic, C. Both glucogenic & ketogenic, D. None
C: Both glucogenic & ketogenic
Answer: C: Both glucogenic & ketogenic 
Explanation: Ans. is 'c' i.e., Both glucogenic & ketogenic GlucogenicKetogenicBoth glucogenic & ketogenico Alanineo Arginineo Aspargineo Aspartic acido Cysteineo Glutamineo Glutamic acido Glycineo Histidineo Methionineo Prolineo Serineo Threonineo Valineo Leucineo Lysineo Isoleucineo Phenylalaineo Tyrosineo TryptophanNote: According to Harper 29th/e (P-282), lysine is both ketogenic and glucogenic. But all other textbooks have mentioned it as ketogenic.