Essential amino acids
Biochemistry   Wikipedia  
Phe
Val
Thr
Trp
Ile
Met
His
Arg
Lue
Lys
Always argues: the A is for Arg, not Asp.
'Never tires': T is not Tyr, but is both Thr and Trp.

 Mnemonic:
"PVT. TIM HALL always argues, never tires"