万物简史 第410期:生命的起源(4)

 Yet we are talking about several hundred thousand types of protein, perhaps a million, 然而，我们在讨论的蛋白质有几十万种，也许是100万种，

each unique and each, as far as we know, vital to the maintenance of a sound and happy you. 就我们所知，每一种都别具一格，与众不同，对于维持你的健康和幸福必不可少。

And it goes on from there. 我们就从这里接着往下讨论。

A protein to be of use must not only assemble amino acids in the right sequence, 为了被派上用场，一个蛋白质分子不但要把氨基酸分子按照合适的顺序排列起来，

but then must engage in a kind of chemical origami and fold itself into a very specific shape. 还要从事一种化学打褶工作，把自己叠成特定的形状。

Even having achieved this structural¹ complexity², a protein is no good to you if it can't reproduce itself, and proteins can't. 即使实现了这种复杂的结构，蛋白质分子对你依然没有用处，除非它能复制自己，而蛋白质分子不会。

For this you need DNA³. 为了达到这个目的，你需要DNA（脱氧核糖核酸）。

DNA is a whiz at replicating—it can make a copy of itself in seconds—but can do virtually nothing else. DNA是复制专家——几秒钟就能复制一份自己，但除此之外没有别的本事中。

So we have a paradoxical situation. 于是，我们处于一种自相矛盾的境地。

Proteins can't exist without DNA, and DNA has no purpose without proteins. 蛋白质分子没有DNA就不能存在，DNA没有蛋白质就无所事事。

Are we to assume then that they arose simultaneously⁴ with the purpose of supporting each other? If so: wow. 那么，我们是不是该认为，它们为了互相支持而同时产生呢？如果是的，哇，太好了！

And there is more still. DNA, proteins, and the other components⁵ of life couldn't prosper⁶ without some sort of membrane⁷ to contain them. 还有，要是没有膜把DNA、蛋白质和别的生命要素包裹起来，它们也不可能兴旺发达。

No atom or molecule⁸ has ever achieved life independently. 原子或分子不会独立实现生命。

Pluck any atom from your body, and it is no more alive than is a grain of sand. 从你身上取上一个原子，它像一粒沙，那样没有生命。

It is only when they come together within the nurturing⁹ refuge of a cell that these diverse materials can take part in the amazing dance that we call life. 只有许多原子凑到一起，待在营养丰富的细胞里，这些不同的物质才能参加令人惊叹的舞会，我们称其为生命。

1 structural   

adj.构造的，组织的，建筑（用）的

参考例句：

• The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
• The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。

2 complexity   

n.复杂(性)，复杂的事物

参考例句：

• Only now did he understand the full complexity of the problem.直到现在他才明白这一问题的全部复杂性。
• The complexity of the road map puzzled me.错综复杂的公路图把我搞糊涂了。

3 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。

4 simultaneously   

adv.同时发生地，同时进行地

参考例句：

• The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
• The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。

5 components   

（机器、设备等的）构成要素，零件，成分； 成分( component的名词复数 )； [物理化学]组分； [数学]分量； （混合物的）组成部分

参考例句：

• the components of a machine 机器部件
• Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

6 prosper   

v.成功，兴隆，昌盛；使成功，使昌隆，繁荣

参考例句：

• With her at the wheel,the company began to prosper.有了她当主管，公司开始兴旺起来。
• It is my earnest wish that this company will continue to prosper.我真诚希望这家公司会继续兴旺发达。

7 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。

8 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

9 nurturing   

养育( nurture的现在分词 )； 培育； 滋长； 助长

参考例句：

• These delicate plants need careful nurturing. 这些幼嫩的植物需要精心培育。
• The modern conservatory is not an environment for nurturing plants. 这个现代化温室的环境不适合培育植物。