評論
打印
Now let's see what happens when Dr. Dolhun adds the gummy bear
下面來看Dolhun博士加入橡皮糖熊會怎樣
Alright, so let's just break down what just happened
好 我來講解一下發生了什么
The sugar from the gummy bear
橡皮糖熊中的糖
and oxygen react to produce carbon dioxide and water
同氧氣反應 生成二氧化碳和水
releasing a lot of energy as heat and light
以熱和光的形式釋放出大量能量
This is what that looks like
情況是這樣的
And I'm going to draw sucrose or sugar in a red
我用紅色來畫蔗糖 這是糖
because that's from the gummy bear
來自于橡皮糖熊
This reaction is probably familiar to you
這個反應你們可能很熟悉
It's a combustion reaction
這是一個燃燒反應
which has been a fuel reacts with oxygen to produce carbon dioxide and water
一種燃料同氧氣反應 生成二氧化碳和水
and at the same time releasing a bunch of energy
同時釋放出大量能量
So why is so much energy released and where does it come from?
為什么釋放出這么多能量 能量來自何方
To show you, I'm going to draw the structures
為了說明這一點 我將畫出結構圖
Now if you're unfamiliar with organic chemistry notation
給不熟悉有機化學表示法的同學解釋下
each of the lines between the elements that I'm going to draw
我要畫的每一條線
represents a covalent bond
都表示一條共價鍵
which is the sharing of two electrons between two atoms
也就是兩原子間共用的兩個電子
So let me draw those
我來畫一下
So here are the reactants
這里是反應物
and here are the products
這里是產物
Now by looking at the number of bonds and the type of bonds so
我們可以觀察鍵的數量和鍵的類型
a carbon bonded to an oxygen
碳同氧之間的鍵
or carbon bonded to a carbon
或碳同碳之間的鍵
and a single bond versus a double bond
還有單鍵同雙鍵之間的區別
you can calculate the energy difference
由此可以計算出
between the left side of the reaction, the reactants
左側反應物和右側產物之間的能量差異
and the right side or the products
左側反應物和右側產物之間的能量差異
Now all combustion reactions
所有燃燒反應
have more energy stored in the reactants than the products
在反應物中儲存的能量都大于產物
So as the reaction progresses
所以隨著反應進行
this energy has to go somewhere and it's released as heat and light
這些能量需要釋放 于是就會生成熱和光
Now the amount of energy released from this explosion
這個爆發中釋放出來的能量
is exactly the same as the amount of energy that would be released
在量上同人體內消化這個橡皮糖熊時完全一樣
in my body when I eat this gummy bear
在量上同人體內消化這個橡皮糖熊時完全一樣
The difference is that proteins in my body are set up in pathways
差異在于 人體內的蛋白質在代謝途徑中有很好的設計
that extract the energy in small manageable bundles
能夠以可控方式逐步少量提取能量
So I power my everyday activities like dancing and running
這樣我就能為日常活動 如跳舞 跑步 提供能量
but I don't explode
但我不會爆掉
Evolution has trained biological systems
進化讓生物系統組織得很好
to efficiently extract energy from our environment
由此能夠有效提取環境中的能量
Alright, that's it for me today. I'll see you next time
好 今天就到這里 下次再見
