41. Among the essential amino acids, which one is a precursor for the
neurotransmitter serotonin?
(A) Tryptophan
(B) Threonine
(C) Valine
(D) Isoleucine
答案:登入後查看
統計: A(5), B(0), C(0), D(1), E(0) #3331935
統計: A(5), B(0), C(0), D(1), E(0) #3331935