题干

胃内的酸性环境是通过质子泵维持的,质子泵催化1分子的ATP水解所释放的能量,可驱动1个H+从胃壁细胞进入胃腔和1个K+从胃腔进入胃壁细胞,K+又可经通道蛋白顺浓度进入胃腔,下列相关叙述错误的是(  )

A:质子泵在上述过程中可能既是酶又是载体

B:K+由胃壁细胞进入胄腔不需要质子泵的作用

C:H+从胃壁细胞进入胃腔需要载体蛋白的协助

D:胃内酸碱度是机体内环境的理化性质之一

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答案(点此获取答案解析)

D

同类题3

阅读下面材料, 从每题所给的A, B, C, D四个选项中选出最佳选项。

C

    Life is full of surprises and you never know how things will turn out. Sir John Gurdon. Is a good example of this. As a boy, he was told he was hopeless at science and finished bottom of his class. Now, aged 79, the very same Gurdon shared the 2012 Nobel Prize in Medicine with Japanese stem cell (干细胞) researcher Shinya Yamanaka.

    Like so many scientists, Gurdon shows us where the power of curiosity and perseverance (坚持) can lead.

    At the age of 15 in 1948, Gurdon ranked last out of the 250 boys at his high school in biology and every other science subject. Gurdon's high school science teacher even said that his dream of becoming a scientist was quite "ridiculous".

    In spite of his teacher's criticisms, Gurdon followed his curiosity and kept working hard. He went to the laboratory earlier and left later than anyone else. He experienced thousands of failures.

    "I believe that we will, in the end, understand everything about how cells actually work." Gurdon said.

    In 1962, Gurdon took a sell from an adult frog and moved its genetic (基因的) information i nto an egg cell. The egg cell then grown into a clone of the adult frog. This technique later helped to create Dolly the sheep in 1996, the first cloned mammal in the world.

    In 2006, Gurdon's work was developed by Yamanaka to show that a sample (样本) of a person's skin can be used to create stem cells. Using the technique, doctors can repair a patient's heart after a heart attack.

    "Luck prefers the prepared mind." Gurdon told the Nobel Prize organization. "Ninety percent of the time things don't work, but when they do, you have to catch the chance."