问题
单项选择题 A1型题
蛋白质合成后经化学修饰的氨基酸是（）
A.丝氨酸
B.酪氨酸
C.半胱氨酸
D.羟脯氨酸
E.蛋（甲硫）氨酸
答案
参考答案：D
解析：蛋白质合成的加工。蛋白质中羟脯氨酸是合成后由脯氨酸残基经羟化修饰而来的。羟脯氨酸不属有遗传密码子的20种氨基酸。
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蛋白质合成后经化学修饰的氨基酸是（）
A.丝氨酸
B.酪氨酸
C.半胱氨酸
D.羟脯氨酸
E.蛋（甲硫）氨酸
参考答案：D
解析：蛋白质合成的加工。蛋白质中羟脯氨酸是合成后由脯氨酸残基经羟化修饰而来的。羟脯氨酸不属有遗传密码子的20种氨基酸。
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| As we all know, Chinese handwriting has infinite power to express differences of character and cultivation. But we have to admit that traditional handwriting has become a 1 art, now that kids start using keyboards as soon as they begin school. However, writing things out by hand may be a 2 way we train our brains, several studies suggest. Many psychologists think that handwriting can make you 3 ! Writing by hand is different from 4 because it requires using strokes to create a letter, 5 just selecting the whole letter by touching a key, says Virginia Berninger, a professor of psychology at the University of Washington. These 6 movements activate large regions of the brain 7 in thinking, memory, and language. Handwriting helps children learn letters and shapes, improves their composition of ideas, and may also 8 fine- motor skills development. A study by Berninger found that in grades two, four, and six, children wrote more words, faster, and expressed more 9 when writing essays by hand than when typing on a keyboard. A separate study by researchers at Indiana University found that children who practiced printing by hand had more active 10 than kids who 11 looked at letters. It's not just children who 12 from writing things out by hand, says a study in the Journal of Cognitive Neuroscience. Adults learning a new language remember its 13 better if they write them out by hand than if they produce them with a keyboard. As more people 14 their days on the computer, says neuroscientist P. Murali Doraiswamy of Duke University, " 15 people in handwriting skills could be a useful cognitive exercise." | ||||
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