Cell vs. virus: A battle for health - Shannon Stiles

细胞对病毒: 为了健康的战争 - 香农•斯蒂尔斯

翻译人员: Taiyi Pan 校对人员: Cora Liu

You're in line at the grocery store when, uh oh,

你在超市里排队，哦，不妙，

someone sneezes on you.

有个人朝你打了个喷嚏。

The cold virus is sucked inside your lungs

感冒病毒被吸到了你的肺里，

and lands on a cell on your airway lining.

然后降落在你气管壁上的一个细胞。

Every living thing on Earth is made of cells,

地球上所有的生命都是由细胞组成的，

from the smallest one-celled bacteria

从最小的单细胞细菌，

to the giant blue whale to you.

到巨大的蓝鲸，到你。

Each cell in your body is surrounded by a cell membrane,

你身体里的每一个细胞都是被细胞膜所包起来。

a thick flexible layer made of fats and proteins,

那是由脂肪和蛋白质组成的一层即厚又软的物质，

that surrounds and protects the inner components.

包围着并保护着细胞内部。

It's semipermeable,

细胞具有半渗透性，

meaning that it lets some thing pass in and out

意味着它让有些东西自由进出，

but blocks others.

但阻挡其它的东西。

The cell membrane is covered with tiny projections.

细胞膜上有很多突出的部分。

They all have functions,

它们都有用处的，

like helping cells adhere to their neighbors

比如帮助细胞吸附住临近的细胞，

or binding to nutrients the cell will need.

或帮细胞链接上营养物质。

Animal and plant cells have cell membranes.

动物细胞和植物细胞都有细胞膜。

Only plant cells have a cell wall,

但是只有植物细胞有细胞壁，

which is made of rigid cellulose that gives the plant structure.

当中坚硬的纤维素给植物制造了他的结构。

The virus cell that was sneezed into your lungs is sneaky.

被打喷嚏进你肺里的病毒体是很狡猾的。

Pretending to be a friend,

它假装是一个朋友，

it attaches to a projection on the cell membrane,

连到细胞膜上的一个突出部分，

and the cell brings it through the cell membrane and inside.

然后细胞让它穿过细胞膜进来。

When the virus gets through,

当病毒在里面了以后，

the cell recognizes its mistake.

细胞认识到它犯的错误。

An enemy is inside!

敌人到里面来了！

Special enzymes arrive at the scene

特殊的酶赶到现场，

and chop the virus to pieces.

把病毒切成数块。

They then send one of the pieces back

之后它们把其中的一块

through the cell membrane,

放到细胞膜外面，

where the cell displays it to warn neighboring cells

这样细胞就可以警示它旁边的细胞：

about the invader.

有入侵者。

A nearby cell sees the warning

旁边一个细胞看到了这个警示，

and immediately goes into action.

立刻开始行动。

It needs to make antibodies,

它需要制造叫做抗体的

proteins that will attack and kill

会攻击并杀掉入侵病毒的

the invading virus.

一种蛋白质。

This process starts in the nucleus.

整个制造流程从细胞核内开始。

The nucleus contains our DNA,

细胞核装有我们的DNA。

the blueprint that tells our cells how to make everything

那是一幅告诉我们细胞怎么制造

our bodies need to function.

我们身体所需的一切东西的蓝图。

A certain section of our DNA contains instructions

我们DNA的一部分有指示

that tell our cells how to make antibodies.

来告诉我们的细胞怎么制造抗体。

Enzymes in the nucleus find the right section of DNA,

细胞核中的酶找到正确的DNA部分，

then create a copy of these instructions,

再制造这些指令的备份，

called messenger RNA.

叫做信使RNA。

The messenger RNA leaves the nucleus to carry out its orders.

信使RNA离开细胞核去执行它的命令。

The messenger RNA travels to a ribosome.

信使RNA到了一个核糖体。

There can be as many as 10 million ribosomes

在一个人体细胞里有

in a human cell,

一千万个核糖体，

all studded along a ribbon-like structure

都集中在一个叫做

called the endoplasmic reticulum.

内质网的结构上。

This ribosome reads the instructions from the nucleus.

这个核糖体解读来自细胞核的指示。

It takes amino acids and links them together one by one

它把氨基酸一个接一个串起来，

creating an antibody protein that will go fight the virus.

制造成一个会攻击病毒的抗体蛋白质。

But before it can do that,

但在那之前，

the antibody needs to leave the cell.

抗体必须得离开细胞。

The antibody heads to the golgi apparatus.

抗体去往高基式体。

Here, it's packed up for delivery outside the cell.

在这里，它会被包装起来向细胞外运输。

Enclosed in a bubble made of the same material as the cell membrane,

包在一个由细胞膜物质组成的泡泡里，

the golgi apparatus also gives the antibody directions,

高基式体也会给抗体指示，

telling it how to get to the edge of the cell.

告诉它怎么去细胞的边缘。

When it gets there,

当它到了那里，

the bubble surrounding the antibody fuses to the cell membrane.

包着抗体的泡泡融入细胞膜。

The cell ejects the antibody,

细胞射出抗体，

and it heads out to track down the virus.

然后抗体去找那病毒。

The leftover bubble will be broken down

剩下的泡泡会被

by the cell's lysosomes

细胞的溶体而分解。

and its pieces recycled over and over again.

它的碎片被重复地回收利用。

Where did the cell get the energy to do all this?

细胞在哪里找来能量去做这些事情？

That's the roll of the mitochondria.

那是线粒体的功能。

To make energy, the mitochondria takes oxygen,

为了制造能量，线粒体吸进氧气。

this is the only reason we breathe it,

这是我们需要氧气的唯一原因。

and adds electrons from the food we eat

然后它加入从我们吃的食物中来的电子

to make water molecules.

去制造水分子。

That process also creates a high energy molecule,

这个过程同时制造出一个高能量分子，

called ATP which the cell uses to power all of its parts.

叫做三磷酸腺苷，为细胞供给能量所用。

Plant cells make energy a different way.

植物细胞通过不同的形式制造能量。

They have chloroplasts

它们有叶绿体。

that combine carbon dioxide and water

叶绿体把二氧化碳和水份

with light energy from the sun

与太阳光能量合成

to create oxygen and sugar,

氧气与糖份，

a form of chemical energy.

一种化学能量。

All the parts of a cell have to work together

细胞所有部分必须得一起工作，

to keep things running smoothly,

才能使一切步骤到位。

and all the cells of your body have to work together

你体内所有的细胞也必须一起工作

to keep you running smoothly.

使你一切正常。

That's a whole lot of cells.

人体内有很多细胞。

Scientists think there are about 37 trillion of them.

科学家们认为人体内有37万亿个细胞。