万物简史 第546期:令人惊叹的细胞(10)

 The membrane¹ is not, as most of us imagine it, a durable², rubbery casing, something that you would need a sharp pin to prick³. 细胞膜并不是我们大多数人想象的那样是一层你用别针能刺穿的耐久胶状物，

Rather, it is made up of a type of fatty material known as a lipid, 相反，它是由一种叫做脂质的脂肪物质所构成，

which has the approximate consistency⁴ "of a light grade of machine oil," to quote Sherwin B. Nuland. 用舍温·B·纽兰的话说，它和“轻度机油”大体相像。

If that seems surprisingly insubstantial, bear in mind that at the microscopic⁵ level things behave differently. 如果你觉得这些东西似乎很不坚实，请记住：在显微镜下，事物的表现形式是不同的。

To anything on a molecular⁶ scale water becomes a kind of heavy-duty gel, and a lipid is like iron. 在分子的层面上，对于任何东西而言，水成了重型凝胶，而脂质简直就像钢铁一样。

If you could visit a cell, you wouldn't like it. 如果你有机会去访问一个细胞，你一定不会喜欢它的。

Blown up to a scale at which atoms were about the size of peas, a cell itself would be a sphere roughly half a mile across, 若是将原子放大到豌豆一样大小，那么一个细胞就会变成直径达800米的一个球体，

and supported by a complex framework of girders called the cytoskeleton. 由一个名叫细胞骨架的大梁似的复杂架子支撑着。

Within it, millions upon millions of objects—some the size of basketballs, others the size of cars—would whiz about like bullets. 在它的里面，几百万几百万个物体——有的大如篮球，有的大如汽车——像子弹一样呼啸而过。

There wouldn't be a place you could stand without being pummeled and ripped thousands of times every second from every direction. 在这里你简直难以找到立足的地方，每一秒钟都会遭到数千次来自四面八方的物体的撞击和撕扯。

Even for its full-time⁷ occupants the inside of a cell is a hazardous⁸ place. 即使对长期待在细胞里面的成员来说，这里也是一个险象环生的地方。

Each strand⁹ of DNA¹⁰ is on average attacked or damaged once every 8.4 seconds—ten thousand times in a day, 每一段DNA链平均每8.4秒就要遭到一次袭击或损害——每天要遭到1万次，

by chemicals and other agents that whack¹¹ into or carelessly slice through it, 被化学物质或是其他物质撞击或撕成碎片，

and each of these wounds must be swiftly stitched up if the cell is not to perish. 所有这些伤口必须很快被缝合，除非细胞不想再活下去。

The proteins are especially lively, spinning, pulsating¹², and flying into each other up to a billion times a second. 蛋白质极为活跃，它们总是处于不停旋转、颤动和飞舞的状态之中，每秒钟它们都要彼此撞击10亿次。

 

1 membrane   

n.薄膜，膜皮，羊皮纸

参考例句：

• A vibrating membrane in the ear helps to convey sounds to the brain.耳膜的振动帮助声音传送到大脑。
• A plastic membrane serves as selective diffusion barrier.一层塑料薄膜起着选择性渗透屏障的作用。

2 durable   

adj.持久的，耐久的

参考例句：

• This raincoat is made of very durable material.这件雨衣是用非常耐用的料子做的。
• They frequently require more major durable purchases.他们经常需要购买耐用消费品。

3 prick   

v.刺伤，刺痛，刺孔；n.刺伤，刺痛

参考例句：

• He felt a sharp prick when he stepped on an upturned nail.当他踩在一个尖朝上的钉子上时，他感到剧烈的疼痛。
• He burst the balloon with a prick of the pin.他用针一戳，气球就爆了。

4 consistency   

n.一贯性，前后一致，稳定性；(液体的)浓度

参考例句：

• Your behaviour lacks consistency.你的行为缺乏一贯性。
• We appreciate the consistency and stability in China and in Chinese politics.我们赞赏中国及其政策的连续性和稳定性。

5 microscopic   

adj.微小的，细微的，极小的，显微的

参考例句：

• It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
• A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。

6 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

7 full-time   

adj.满工作日的或工作周的，全时间的

参考例句：

• A full-time job may be too much for her.全天工作她恐怕吃不消。
• I don't know how she copes with looking after her family and doing a full-time job.既要照顾家庭又要全天工作，我不知道她是如何对付的。

8 hazardous   

adj.(有)危险的，冒险的；碰运气的

参考例句：

• These conditions are very hazardous for shipping.这些情况对航海非常不利。
• Everybody said that it was a hazardous investment.大家都说那是一次危险的投资。

9 strand   

vt.使（船）搁浅，使（某人）困于（某地）

参考例句：

• She tucked a loose strand of hair behind her ears.她把一缕散发夹到了耳后。
• The climbers had been stranded by a storm.登山者被暴风雨困住了。

10 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

11 whack   

v.敲击，重打，瓜分；n.重击，重打，尝试，一份

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• He gave me a whack on the back to wake me up.他为把我弄醒，在我背上猛拍一下。

12 pulsating   

adj.搏动的，脉冲的v.有节奏地舒张及收缩( pulsate的现在分词 )；跳动；脉动；受（激情）震动

参考例句：

• Lights were pulsating in the sky. 天空有闪烁的光。
• Spindles and fingers moved so quickly that the workshop seemed to be one great nervously-pulsating machine. 工作很紧张，全车间是一个飞快的转轮。 来自子夜部分