多聚体是由许多相同或相似的小分子(单体)组成的长链,下图表示细胞利用单体合成多聚体的

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问题:

多聚体是由许多相同或相似的小分子(单体)组成的长链,下图表示细胞利用单体合成多聚体的示意图,回答有关问题:

生物体中合成的大分子种类很多,仅蛋白质种类就约有1012种,蛋白质之所以具有多样性,原因有:氨基酸的(),数目(),以及()的空间结构不同

 

考点:高中生物组成细胞的分子组成细胞的分子题库
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For more than two centuries, American’s colleges and universities have been the backbone of the country’s progress. They have educated the technical, managerial, (1) and provided generation after generation of national leaders. Today educators from around the globe are turning to U. S. institutions of higher learning (2) . They are apt to find many reasons for the excellence of American universities, but (3) stand out as watersheds:
Education (4) : In 1862 Congress enacted the Land-Grant College Act, which essentially extended the opportunity of higher education (5) , including such disenfranchised groups as women and minorities. Each state was permitted to sell large tracts of (6) and use the proceeds to endow at least one public college.
(7) : Over the years, the decentralization and diversity of the America’s colleges and universities have promoted competition for students and resources. Competitive pressure first arose (8) . The academy’s impact really grew after World War II, when (9) commissioned by President Roosevelt argued that it was the federal government’s responsibility to (10) for basic research. Instead of being centralized in government laboratories, scientific research (11) in American universities and generated increasing investment. It also gave graduate students research opportunities and helped (12) far and wide, to the benefit of industry, medicine and society as a whole.
(13) : The end of the World War II saw passage of the Servicemen’s Readjustment Act of 1944. The law, which provided for (14) for returning veterans, made an already democratic higher-education system accessible in ways that were (15) in Europe, opening the doors of the best universities to men and women who had (16) of going to college.
(17) : The creation of federal loan guarantees and subsidy programs, as well as outright grants for college students brought (18) to higher education and further helped to democratize access. Since its founding (19) , the Federal Family Education Loan Program has funded more than 74 million student loans worth more than (20) .

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下列有关涂装的叙述正确的是( )。

A.涂装的环境温度应控制在25℃以上

B.涂装的相对湿度不应大于85%

C.涂装后2h内应保护免受淋雨,2h后不再设防

D.涂装遍数可以施工单位自行决定

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林业有害生物防治资金的使用范围包括哪些方面?

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在选定两家以上供应商的基础上,由供应商经几轮报价,最后选择报价最低者的采购方式为( )采购。

A.招标
B.议价
C.询价
D.竞争性谈判

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2009年1-4月我国完成城镇固定资产投资为37082.30亿元,比去年同期增长30.5%,其中第一产业比去年同期增长82.1%,投资比重见下图。

2009年1-4月我国完成的城镇固定资产投资项目中,地方项目完成多少亿元()

A.30346.34

B.31236.61

C.33633.65

D.34580.12

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