单选题在天然蛋向质的组成中，不含有的氨基酸是( )(2009年)

单选题原核核糖体上结合氨基酰tRNA的氨基酰位的位置是

单选题It is generally recognized in the world that the second Gulf War in Iraq is a crucial test of high-speed web. For decades, Americans have anxiously (1) each war through a new communication (2) , from the early silent film of World War I to the 24-hour cable news (3) of the first Persian Gulf War. Now, (4) bombs exploding in Baghdad, a sudden increase in wartime (5) for online news has become a central test of the (6) of high-speed Internet connections. It is also a good (7) both to attract users to online media (8) and to persuade them to pay for the material they find there, (9) the value of the Cable News Network persuaded millions to (10) to cable during the last war in Iraq. (11) by a steady rise over the last 18 months in the number of people with high-speed Internet (12) , now at more than 70 million in the United States, the web sites of many of the major news organizations have (13) assembled a novel collage (拼贴) of (14) video, audio reports, photography collections, animated weaponry (15) , interactive maps and other new digital reportage. These Internet services are (16) on the remarkable abundance of sounds and images (17) from video cameras (18) on Baghdad and journalists traveling with troops. And they have found a (19) audience of American office workers (20) their computers during the early combat.

单选题真核生物的DNA聚合酶

单选题当肝细胞内ATP供应充分时，下列叙述哪一项是错误的

单选题蛋白质分子中的α-螺旋和β-片层都属于

单选题属于肝己糖激酶的同工酶类型是( )(2012年)

单选题A.rRNAB.tRNAC.mRNAD.hnRNA

单选题不能作为细胞内信号转导第二信使的物质是

单选题柠檬酸是下列哪种酶的变构激活剂

单选题糖原分解的关键酶是

单选题反式作用因子的确切定义是指

单选题真核生物DNA缠绕在组蛋白上构成核小体，核小体含有的蛋白质是

单选题A．IeuB．GlyC．二者都是D．二者都不是 (2001年)

单选题1摩尔葡萄糖经糖酵解净生成几摩尔ATP

单选题天冬氨酸、乳酸和甘油异生为糖时，所经历的共同反应是

单选题关于增强子的叙述，不正确的是

单选题A．二级结构 B．结构域C．模体 D．三级结构E．四级结构

单选题关于蛋白质亚基的描述，正确的是

单选题一个DNA分子中，若G所占的摩尔比是32．8％，则A的摩尔比应是