The simple story of photosynthesis and food - Amanda Ooten

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

翻译人员: Minji Seo 校对人员: Yolanda Zhang

Ever wonder where most of the food

有没有想过你每天吃的食物

you eat every day comes from?

大部分都是从哪里来的？

Well, about 60% of the food you eat

事实上，大约60%的食物是

is carbohydrates.

碳水化合物。

As you can probably tell from its name,

从名字或许就会看出，

carbohydrates contain carbon,

碳水化合物包含碳，

hydrogen,

and oxygen.

氢，

和氧气。

But where do these atoms originally come from

但是这些原子最初来自哪里呢？

and how do they join together

它们又是如何组合来产生

to make delicious foods like fruits and pasta?

美味的食物，如水果和意大利面的呢？

It actually all starts with the air

实际上，一切都是从你此刻

you are exhaling this very minute,

呼吸的空气开始的，

specifically the carbon dioxide molecules.

尤其是二氧化碳分子。

Plants are going to breath in

植物会通过

this very same carbon dioxide

其表面的气孔

through pores in their skin, called stomata.

吸入这些二氧化碳。

Plants drink in water from their roots

植物还会通过根茎从土壤吸收水分，

to get the needed oxygen and hydrogen atoms,

以获得所需的氧和氢原子，

and their electrons,

以及它们的电子，

in order to build carbohydrates.

从而产生碳水化合物。

What is that thing?

那是什么?

Well, that's a special plant organelle

哦，那是一个特殊的植物细胞器，

inside the leaves of plants

在植物的叶子内，

called a chloroplast.

叫叶绿体。

It's green beceause of a special light-absorbing pigment

由于一种特殊的 称作叶绿素的采光色素，

called chlorophyll.

它才是绿色的。

Each leaf has about 44,000 cells

每片叶子有大约4万4千个细胞，

and every cell can have anywhere

每个细胞含有

between 20 to 100 chloroplasts.

20到100个叶绿体。

That's up to 4,400,000 chloroplasts!

算下来有最多440万个叶绿体！

By now, you've probably guessed

现在，你也许已经猜到

that we're talking about the process of photosynthesis

我们在讨论光合作用的过程，

and you might be wondering

你也许想知道

when the sun is going to make its entrance.

太阳是怎么参与这个过程的。

Let's go back to that original molecule of water.

让我们回到水原来的分子状态。

The plant has to split this molecule of water

植物必须将水分子分解，

so it can get electrons from it.

以获取其中的电子。

But, the plant can't pull that water apart by itself.

但是，植物本身不能分解水分子，

It needs help from the high-energy rays of the sun.

它需要来自太阳的高能射线的帮助。

So now that the chloroplast has all the building blocks

现在叶绿体有了所有的构件：

- carbon, hydrogen, oxygen, and electrons -

碳，氢，氧气和电子，

it can use them to go through

叶绿体利用这些构件来完成

the rest of the steps of photosynthesis

光合作用的剩余步骤，

to transform that original carbon dioxide gas

将原始的二氧化碳气体转化为

into a simple carbohydrate called glucose,

一种简单的碳水化合物：葡萄糖，

C-6-H-12-O-6.

C-6-H-12-O-6。

That little glucose molecule then helps to build

然后，这个小小的葡萄糖协助生成

bigger and better carbohydrates

更大更高等的碳水化合物，

like cellulose.

比如纤维素。

Cellulose is a type of carbohydrate found in plants

纤维素是在植物中发现的 一种碳水化合物，

that our body cannot break down.

人类的身体无法分解它。

We call it fiber

我们称之为纤维，

and we eat it in vegetables like lettuce,

可以在蔬菜中吃到，如莴苣，

broccoli,

and celery.

西兰花，

和芹菜。

Plants use cellulose to keep themselves strong.

纤维素可以保持植物的坚韧度。

The plant could also turn that glucose into starch,

植物也可以将葡萄糖转化为淀粉，

a large molecule that stores energy for the plant.

一种帮助植物存储能量的大分子。

We love eating starch from plants like potatoes,

大家喜欢吃来自食物的淀粉，如土豆，

corn,

and rice.

玉米，

和大米。

So you see, when you eat plants,

所以，当你吃植物的时候，

we're actually benefiting from photosynthesis.

实际上是受益于光合作用。

The plant makes things like starch,

植物生产我们能吃的东西，

which we eat

例如淀粉，

and then break back down into glucose,

然后分解成葡萄糖，

the first form the plant made.

即其初始形态。

Then, the mitochondria in our cells,

接着，我们体内的线粒体，

powered by the oxygen we breath,

由我们吸入的氧气提供动力，

can turn glucose into pure energy molecules

能将葡萄糖转化为纯粹的能量分子，

called ATP.

叫做ATP。

ATP powers all work done

每一个细胞完成的事情，

by each and every one of your cells,

全部是由ATP提供动力的，

things like communication,

比如通讯，

movement,

移动，

and transport.

和传递。

But why do we have to turn that glucose into ATP?

但为什么我们必须将 葡萄糖转化为ATP?

Well, think of it like this.

可以这样理解。

You're excited to start your summer job

你很高兴开始

at the local ice cream stand,

本地冰激淋店的暑期工，

but your boss has just told you

但你老板告诉你，

that she is going to pay you in ice cream cones.

你的报酬是甜筒。

What are you going to be able to do

你能怎么处理

with those ice cream cones?

这些甜筒呢？

Nothing,

什么也做不了，

which is why you kindly asked to be paid in dollars.

这就是你为什么要求 以美元支付你的薪酬。

ATP is just like dollars.

ATP就相当于美元。

It is the currency that all cells of life use

它是生命体所有细胞共同使用的货币，

while glucose is,

至于葡萄糖，

well, kind of like ice cream.

就类似于冰激淋。

Even plants have mitochondria in their cells

每个植物细胞也都有线粒体，

to break down the glucose they make into ATP.

能将生成的葡萄糖分解成ATP。

So as you can see,

正如你看到的，

humans and plants are intricately connected.

人类和植物之间有着复杂的联系。

The air we breath out

我们呼出的空气

is used by plants to make the carbohydrates

被植物用来生成我们喜爱的

we enjoy so much.

碳水化合物。

And, in the process,

于此同时，

they are releasing the very same oxygen molecules

植物也会释放出我们需要吸入的

we need to breath in

氧气分子，

in order that our mitochondria can break down

这样我们细胞内的线粒体就能分解

our delicous carbohydrate meal.

我们吃掉的碳水化合物美食了。