The answer is a neverending series of reactions that are dedicated to doing two vital, and totally contradictory, things: One set of chemical reactions destroys the reactants that you give them, reducing big, complex substances into molecular rubble.

答案是一系列无休止反，这些反致力于做两件至关重要且完全矛盾事情：一组化学反会破坏你给它们反，将大型复杂成分子碎片。

But how does the leaf prevent unwanted intruders, like bacteria from getting in and stop important reactants from escaping?

但是，叶子要如何防止不必要入侵者（如细菌）进入并阻止重要反逸出？

Reactants become products and that's that.

反成产，仅此而已。

Below that is the spongy mesophyll, which have plenty of space in between them for reactants to move through.

下面是海绵状中叶，它们之有足够供反移动通过。

A leaf is like a plant's food factory — and its parts work together to get the reactants into one place so that photosynthesis can happen.

叶子就像植食品工厂——它各个部分一起工作，把反带到一个地方，这样就可以进行光合作用。

And so what are the reactants here?

这里反是什么？

So it's going to convert certain reactants into products.

因此，它将把某些反转化为产。

Right here I've got one of my other reactants.

这儿有我另一种反。

So if we were to find the reverse rate law for a reaction it would take the same form as the forward one, but using the initial concentrations for the products rather than the reactants.

所以如果我们想要找到一个反逆向速率定律，它形式会与正向一样，但是使用产初始浓度而不是反初始浓度。

We say a change shifts the reaction to the right if it tends to make more products form and to the left if it tends to make more reactants form.

我们说，如果一种化倾向于形成更多产， 那么它会将反向右移动；如果它倾向于形成更多反， 则它会向左移动。

The enthalpy change for a reaction is equal to the sum of the standard enthalpies of formation of the products, minus the sum of the standard enthalpies of formation of the reactants.

反焓等于产标准生成焓之和减去反标准生成焓之和。

Think of like an imaginary reaction A plus B yields C plus D. The lower case letters represent the coefficients of the reactants and products.

想象一个反 A 加上 B 生成 C 加上 D。小写字母代表反和生成系数。

The more reactants you put in, the more chance they're going to bounce around and be able to react with each other.

你投入反越多，它们相互碰撞并发生反机会就越大。

We could measure the products that are created or we could measure the amount of reactants that are being consumed.

我们可以测量生成产，或者测量正在被消耗反量。

And also we can use our pKa values, which is remember looking at the concentration of reactants and products.

我们还可以使用 pKa 值，记住查看反和产浓度。