47.在肌肉細胞中，轉胺酶（transaminase )可將胺基轉移給下列何者，以生成麩胺酸 (glutamic acid ) ? (A) a-酮戊二酸（a-ketoglutarate) (B)天門冬胺酸（aspartic acid ) (C)麩醯胺酸（glutamine ) (D)丙胺酸（alanine )