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Now let's see what happens when Dr. Dolhun adds the gummy bear
下面来看Dolhun博士加入橡皮糖熊会怎样
Alright, so let's just break down what just happened
好 我来讲解一下发生了什么
The sugar from the gummy bear
橡皮糖熊中的糖
and oxygen react to produce carbon dioxide and water
同氧气反应 生成二氧化碳和水
releasing a lot of energy as heat and light
以热和光的形式释放出大量能量
This is what that looks like
情况是这样的
And I'm going to draw sucrose or sugar in a red
我用红色来画蔗糖 这是糖
because that's from the gummy bear
来自于橡皮糖熊
This reaction is probably familiar to you
这个反应你们可能很熟悉
It's a combustion reaction
这是一个燃烧反应
which has been a fuel reacts with oxygen to produce carbon dioxide and water
一种燃料同氧气反应 生成二氧化碳和水
and at the same time releasing a bunch of energy
同时释放出大量能量
So why is so much energy released and where does it come from?
为什么释放出这么多能量 能量来自何方
To show you, I'm going to draw the structures
为了说明这一点 我将画出结构图
Now if you're unfamiliar with organic chemistry notation
给不熟悉有机化学表示法的同学解释下
each of the lines between the elements that I'm going to draw
我要画的每一条线
represents a covalent bond
都表示一条共价键
which is the sharing of two electrons between two atoms
也就是两原子间共用的两个电子
So let me draw those
我来画一下
So here are the reactants
这里是反应物
and here are the products
这里是产物
Now by looking at the number of bonds and the type of bonds so
我们可以观察键的数量和键的类型
a carbon bonded to an oxygen
碳同氧之间的键
or carbon bonded to a carbon
或碳同碳之间的键
and a single bond versus a double bond
还有单键同双键之间的区别
you can calculate the energy difference
由此可以计算出
between the left side of the reaction, the reactants
左侧反应物和右侧产物之间的能量差异
and the right side or the products
左侧反应物和右侧产物之间的能量差异
Now all combustion reactions
所有燃烧反应
have more energy stored in the reactants than the products
在反应物中储存的能量都大于产物
So as the reaction progresses
所以随着反应进行
this energy has to go somewhere and it's released as heat and light
这些能量需要释放 于是就会生成热和光
Now the amount of energy released from this explosion
这个爆发中释放出来的能量
is exactly the same as the amount of energy that would be released
在量上同人体内消化这个橡皮糖熊时完全一样
in my body when I eat this gummy bear
在量上同人体内消化这个橡皮糖熊时完全一样
The difference is that proteins in my body are set up in pathways
差异在于 人体内的蛋白质在代谢途径中有很好的设计
that extract the energy in small manageable bundles
能够以可控方式逐步少量提取能量
So I power my everyday activities like dancing and running
这样我就能为日常活动 如跳舞 跑步 提供能量
but I don't explode
但我不会爆掉
Evolution has trained biological systems
进化让生物系统组织得很好
to efficiently extract energy from our environment
由此能够有效提取环境中的能量
Alright, that's it for me today. I'll see you next time
好 今天就到这里 下次再见
