蛋白质合成时,肽链合成终止的原因是()。A、特异的tRNA识别终止密码 B、已到达m

题型:单项选择题

问题:

蛋白质合成时,肽链合成终止的原因是()。

A、特异的tRNA识别终止密码

B、已到达mRNA分子的尽头

C、终止密码本身具酯酶活性,可将肽链水解下来

D、终止因子能识别终止密码并进入受位

E、终止密码部位有较大阻力,核糖体无法沿mRNA再向3'端移动

考点:化学工程生物化学生物化学题库
题型:单项选择题

病历摘要:患者男性,70岁。因阵发性腹痛、恶心呕吐两天急诊入院。体检:体温38℃,脉搏100次/分,呼吸28次/分,血压15/10kPa,痛苦面容,低声呻吟,强迫体位。腹部稍膨隆,可见肠型及蠕动波,肠鸣音亢进,可闻及气过水声,腹肌稍紧张,右侧腹部触及有压痛包块。X线检查可见右侧肠腔充气并有2-3个液平面。

下列哪些症状与患者的疾病有关?()

A.呃逆

B.腹部反跳痛

C.腹胀

D.黄疸

E.排便困难

F.皮肤干燥,弹性差

G.水肿

H.停止排气

题型:单项选择题

This was one of my experiences (1) . When I was in my 30s, I was working for a large international company which had its head office in London. I was working in the (2) department.

The company had a training centre which was just outside London. Different courses were held there throughout (3) and I (4) go on one training course a year. These usually started (5) a Sunday evening and lasted six days.

Once I was (6) a week’s training course with about forty (7) sales people. I was in the bar on the Friday evening and suddenly a woman who was (8) behind the bar asked mea curious question. "I hope you don’t (9) my asking," she said, "but I’ve been (10) about it all week. Have you got a sister (11) Mary" The woman’s name was June. And she used to do various jobs at the training centre. She worked in the office, she organized all the food and drink for the centre and she worked in the bar at lunchtime and in the evening.

My answer (12) June’s question was "Yes", and June said, "I thought (13) . I met her last September when she was organizing a course here. " At that time, my sister was working for (14) company but in a different part of the country. That was (15) she came to be at the training centre.

(16) surprised me was how June guessed we were brother and sister. Three things made it even more (17) . First, she had met my sister six months before she met me. Second, they have about sixty new people every week at the training centre. So about one thousand five hundred people had (18) the centre in those six months. And (19) , my sister is married, so she doesn’t have the same family name as me.

We’re not (20) , but I guess we must look quite like each other.

6().

A.on

B.in

C.during

D.over

题型:单项选择题

甲和乙签订了房屋租赁合同。其租赁期限最长可为()。

A.10年 

B.20年 

C.30年 

D.50年

题型:单项选择题

我国每年税收宣传月为()

A、3月

B、4月

C、5月

D、6月

题型:单项选择题

压力或温度计中的毛细管越长,则仪表仅应时间越()。

A.快

B.慢

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