[請教]OG-164(沒人問過)

agk99

164. Useful protein drugs, such as insulin, must still be administered by the cumbersome procedure of injection under the skin. If proteins are taken orally, they are digested and cannot reach their target cells. Certain nonprotein drugs, however, contain chemical bonds that are not broken down by the digestive system. They can, thus, be taken orally.

The statements above most strongly support a claim that a research procedure that successfully accomplishes which of the following would be beneficial to users of protein drugs?

(A) Coating insulin with compounds that are broken down by target cells, but whose chemical bonds are resistant to digestion

(B) Converting into protein compounds, by procedures that work in the laboratory, the nonprotein drugs that resist digestion

(C) Removing permanently from the digestive system any substances that digest proteins

(D) Determining, in a systematic way, what enzymes and bacteria are present in the normal digestive system and whether they tend to be broken down within the body A

(E) Determining the amount of time each nonprotein drug takes to reach its target cells.

請教各位，我這一題題目還可以懂，但選項就真的看不懂了，怎麼選也選不出A，請各位幫忙一下

agk99

查過字典，coating是指包裹在外層的東西

那麼是否可以解釋成，包裹一個可以被目標細胞吸收，但卻不會被消化系統給吸收的insulin，也就是做為原文的結論?

(我就是卡在coating，邏輯就是閱讀，沒話說)

Daffi

我的解题思路：

1、先看问题，需要CONCLUSION；

2、回到题目，题目中三层意思：a. 一些 useful protein drugs 需要 injection under the skin；b. 口服（非 injection）将导致被吸收（digested）而 cannot reach target cells；c. 一些 nonprotein drugs 能被口服，因为不能被 digested ；

3、自己得出结论：如果那些 protein drugs 也能被 digested，它就也能被口服了。

4、看选项。A 选项里有很醒目的 insulin（即上面的 protein drugs）以及 resistant to ingestion. 就它了。B 说的是把 nonprotein drugs convert into protein drugs, convert 过来又怎样，protein drugs 照样没法口服；C把 digestive system 的影响因素全部去掉，也是有效的，只是太狠了点（一个 permanently 看得心里发毛），跟A相比，还是后者好；D和E都出现文章里没见过的新东西（enzymes and bacteria 和 amount of time），不理它。

skidals

还是不太明白og中关于c的解释：

If removing substances that digest proteins (choice C) enabled protein drugs to be taken orally, it would be at the expense of normal digestive function.

太不人道了？

snowjing

以下是引用Daffi在2004-11-30 10:36:00的发言：

我的解题思路：

3、自己得出结论：如果那些 protein drugs 也能被 digested，它就也能被口服了。

这个理解有点出入.

文章第二句话, 意思是protein口服则被消化, 无法达到target cells, 即无法其作用.

文章第三句话, 描述了nonprotein drugs不会被消化, 而可以口服.

预期推理是: 不被digested是口服的必要条件, 即 be taken orally-->not broken down or cannot be digested.

A选项是最佳选择:  Coating insulin有chemical bonds不被消化, 又"with compounds that are broken down by target cells".  这里要注意的是原文中的broken down 和 选项A中的broken down 施动者不同, by的对象也不同. 不要混淆. 大家仔细看看.

个人理解, 大家讨论!

snowjing

以下是引用skidals在2004-12-19 0:55:00的发言：

还是不太明白og中关于c的解释：

If removing substances that digest proteins (choice C) enabled protein drugs to be taken orally, it would be at the expense of normal digestive function.

太不人道了？

C的意思是: 永久性去掉消化系统里任何可以消化proteins的物质.

但这些物质除了消化proteins以外, 它们也有normal digestive function. (想象一下, 人除了蛋白质要消化, 还要消化脂肪、纤维等等).

若这样做, 同时也把正常功能给永久性地取消掉了, 得不偿失. 所以OG解释到: at the expense of...

gonghao

up

gonghao

B

有个小问题，对于A没有问题

把蛋白质药物做成非蛋白质结构的衍生物，当到达target cell后，衍生物经过化学变化，再变成蛋白质药物，这样为什么不行啊

理论上是说的通的啊

shellcxw

to gonghao:

你对b的理解正好反了，应该是把非蛋白convert成蛋白啊，不是正好使injection成为必需了么？

太晚

这个coating厉害，居然能保证coating了insulin后还能穿出消化系统到达target cell。target Cell 应该不会在消化道里吧。还不如象楼上说的用化学方法结合insulin。 这个coating不会是化学方式分子层面的结合吧。有人能确认coating后还可以小到穿过消化系统吗？