Activation energy: Kickstarting chemical reactions - Vance Kite

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

翻译人员: Rongpei Yang 校对人员: Jiawei Ni

现在，你身体的细胞里正在嗡嗡地发生着

Right now, trillions of chemical reactions

are humming away in the cells of your body.

数万亿次的化学反应

You never feel them,

你从不会感觉到

but without these reactions,

但没有这些反应

you wouldn't be alive.

你就没有办法生存

Unfortunately, each of those reactions needs some help.

不幸的是，每个反应都需要一些帮助

You see, most molecules are stable,

你看，大部分的分子都是稳定的

they are happy just the way they are.

它们非常享受现在的状态

The atoms in them are all bound-up and friendly with one another

分子里的原子都紧密友好地相互围绕

and would prefer to stay that way.

而且都更喜欢这样的方式

The problem is, for a chemical reaction to happen,

问题是，为了让一个化学反应发生

the atoms that make up those stable molecules

分子里原本处于稳定状态的原子

need to break away from their friends

就需要和它们的伙伴分开

and go buddy up with another atom.

去巴结其他的原子

This break-up is where the molecules need a hand.

如何让原子们分手，就是分子们需要帮忙的关键点

This initial kick-start is known as activation energy.

活化能被视为初始的动力

It's used to destabilize the molecule,

它被用来让分子失去稳定

to push the bonds between the atoms

打破原子间的联系

to a place where they are ready to break.

去到需要它们的地方

This unstable state is known as the molecule's transition state.

这种不稳定的状态就是分子的过渡态

Once a transition state has been achieved,

一旦达到过渡态

the atoms become willing to leave their current molecular friends

原子们就会愿意离开他们现在的分子朋友

and go make new friends elsewhere.

到其他地方交新朋友

Once they are convinced, it's a piece of cake.

一旦它们被说服，事情就简单啦

Bonds break,

连接被打破

atoms rearrange,

原子重新组合

and the rest of the reaction happens automatically.

剩下的反应就理所当然地发生了

After that first push, the body doesn't need to put in

一旦推了这一把

any more energy to help the reaction along.

身体就不需要再动用其他的能量帮助进行反应

Left alone, most of these reactions would be very slow

不受打扰的话，大多数的反应都是很慢的

because it takes quite a while to build up

因为它需要一些时间来生成活化能

the activation energy the molecules need to get started.

让分子完成重组

Enter the enzyme.

让我们来认识酶

Enzymes are proteins that speed up,

酶是一种蛋白质

or catalyze, reactions

它可以通过通过降低活化能

by lowering the activation energy.

让反应加速或者是催化反应

They make it easier for the molecule,

这时的分子就是酶作用物

also known as a substrate,

to get to the transition state.

让分子能够更加容易地达到过渡态

You can think of a reaction like a race.

你可以把一次反应想象成一场比赛

Some racers are running along,

一些参赛者是自己跑

while others have teammates to help them.

而其他的参赛者有队友帮助他们

Meet Sam the Substrate.

让我们来看看酶作用物 Sam

His team is the MODS Squad.

它的团队是 MODS 小组

Together, his team is able to get to the finish faster,

聚在一起，它的团队就能够让比赛结束得更快

using less energy.

而且消耗的能量更少

There are four special enzymes in Sam's team.

在 Sam 的团队里有四种特殊的酶

Each has a different strategy

为了让耗能降低

for lowering the energy it takes to get going

每一个都有自己的策略

and speeding up the pace to get the MODS to the finish line.

并且想办法让团队能够加速到达终点线

The "M" stands for "microenvironment".

"M" 表示「微环境」

This enzyme creates a tiny, special environment for the substrate,

酶会为酶作用物创造一个微小的、特殊的环境

resulting in a faster reaction time.

这能够让反应时间加快

He runs ahead of the pack,

它就能够在被清理平坦的路上顺利前进

flattening out bumps in the road

and misting cool water on his team of molecules.

而且整个分子团队还有冰水照顾

"O" is for "orientation".

"O" 是「定位」

Sometimes two molecules must be positioned

有些时候两个分子在反应之前

just right before they will react.

必须被定位

Like a friend at the finish line,

就像是一个朋友在终点线

the O enzyme provides his molecules

O 酶就为它的分子提供特殊形状的空间

with specially shaped spaces

that allow the substrates to interact in just the right way.

就能让酶作用物们以正确的方式相互作用

"D" stands for "direct participation".

"D" 表示「直接参与」

Every now and again, a little muscle is needed.

每一个时刻都几乎不需要肌肉参与

And when his teammates are struggling to finish the race,

当它的队友们都在向着比赛的终点挣扎的时候

Teammate D is there to pick them up

队友 D 就搭上他们

and carry them over the line.

直接把它们搬到终点线

Finally, "S" is for "straining bonds".

最后，"S" 表示「拉紧连接」

This guy pushes the team

队友 S 通过一些剧烈的弹性运动

through some serious flexibility exercises:

推动整个队伍

splits,

劈开

lunges,

戳

backbends,

下腰

the works.

类似这些高难度的动作

Sometimes his substrate teammates

有些时候它的酶作用物队友

just need to be stressed and flexed

只是需要挤压和弯曲

into their transition state.

让它进入过渡态

So that's it.

这就是酶

Remember that all reactions need energy to get going.

要记住所有的反应都是需要能量的支持

This energy is known as the activation energy.

这种能量就是活化能

Enzymes lower that activation energy

酶可以将需要的活化能降低

and speed the reaction through team MODS:

通过 MODS 小组加快反应速度

microenvironment,

微环境

orientation,

定位

direct participation,

直接参与

and straining bonds.

拉紧连接