hce_kmu
110年
普通生物及生化概論
第 72 題
Which of the following statements about lac operon is CORRECT? ① The repressor is the protein product of lac Z gene. ② The lac operon can be turned on by β-galactoside. ③ Repressor binds to the operator and blocks the binding of RNA polymerase to promoter. ④ Isopropyl-β-D-thiogalactoside can bind to Lac repressor to turn on protein expression. ⑤ In the lac operon model, the genes within the operon will be expressed if lactose is present in E. coli.
- A ①,②,③
- B ①,②,④
- C ②,③,④
- D ③,④,⑤
- E ②,③,④,⑤
思路引導 VIP
試著思考一下：如果一個細胞想要在『特定養分出現』時才開始製造分解該養分的工具（酵素），那麼在平時沒有養分的時候，DNA 上應該具備什麼樣的『物理結構』來防止資源浪費？而當養分（訊號）進入細胞後，這個訊號分子必須與哪個零件結合，才能讓生產線重新運作？