问题
单项选择题
蛋白质分子中的a螺旋和β片层都属于
A.一级结构
B.二级结构
C.三级结构
D.四级结构
E.域结构
答案
参考答案:B
解析:a螺旋和β片层都是指多肽链某一区段中氨基酸残基骨架空间排列的两种形式,属于二级结构。
蛋白质分子中的a螺旋和β片层都属于
A.一级结构
B.二级结构
C.三级结构
D.四级结构
E.域结构
参考答案:B
解析:a螺旋和β片层都是指多肽链某一区段中氨基酸残基骨架空间排列的两种形式,属于二级结构。
阅读理解。 | ||||
Here are two letters to George and his replies. | ||||
| ||||
1. Alice is worrying about ___. | ||||
A. her friends B. her marks C. her height D. her weight | ||||
2. Bob should ___ according to george's letter. | ||||
A. take more exercise B. talk to his friends C. join a basketball team D. leam some French | ||||
3. Ceorge advises Alice to talk to___ for help. | ||||
A. her mother B. her teacher C. Bob's teacher D. Bob's friends |