问题
单项选择题
DTMP是由下列哪种核苷酸直接转变来的
A．TDP
B．TMP
C．dUDP
D．dCMP
E．dUMP
答案
参考答案：E
解析：[解题思路] dTMP是由dUMP经酶促甲基化后形成的。要注意这是特例，因脱氧腺嘌呤、脱氧鸟嘌呤和脱氧胞嘧啶都是在二磷酸核苷水平上由桉糖核苷酸还原酶催化而成的。[命题规律] 考察“嘧啶核苷酸的合成”．必须掌握。
搜题请搜索小程序“爱下问搜题”
DTMP是由下列哪种核苷酸直接转变来的
A．TDP
B．TMP
C．dUDP
D．dCMP
E．dUMP
参考答案：E
解析：[解题思路] dTMP是由dUMP经酶促甲基化后形成的。要注意这是特例，因脱氧腺嘌呤、脱氧鸟嘌呤和脱氧胞嘧啶都是在二磷酸核苷水平上由桉糖核苷酸还原酶催化而成的。[命题规律] 考察“嘧啶核苷酸的合成”．必须掌握。
The responsibility （职责） of students is to study. But studying requires （要求） the right way, 1 The following are the ways of studying. 2 Because in the morning, the air is fresh and the mind is Clear. For that reason we can get good results. 3 If we have not known a text well, we must read it again. We should not read the next one till we have learned the first one well. When we are studying, we must put our heart into the book, 4 We must always ask "Why" . If something is not well understood, write it down and ask our teachers, parents or friends. 5 Though there are many ways of studying, the above-mentioned will be quite enough if we can keep them in mind and do so.
|