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.

答案一系列无休止的反，这些反致力于做两件至关重要且完全矛盾的事情：一组化学反会破坏你给它们的反物，将大型复杂物质变成分子碎片。

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

，子要如何防止不必要的入侵者（如细菌）进入并阻止重要的反物逸出？

Reactants become products and that's that.

反物变成产物，仅此而已。

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

海绵状中，它们之间有足够的空间供反物移动通过。

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.

子就像植物的食品工厂——它的各个部分一起工作，把反物带到一个地方，这样就可以进行光合作用。

And so what are the reactants here?

这里的反物什么？

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

因此，它将把某些反物转化为产物。

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

这儿有我的另一种反物。

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的逆向速率定律，它的形式会与正向的一样，使用产物的初始浓度而不反物的初始浓度。

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，如果一种变化倾向于形成更多的产物， 那么它会将反向右移动；如果它倾向于形成更多的反物， 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.

反的焓变等于产物的标准生成焓之和减去反物的标准生成焓之和。

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。小写字母代表反物和生成物的系数。

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

你投入的反物越多，它们相互碰撞并发生反的机会就越大。

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

我们可以测量生成的产物，或者测量正在被消耗的反物的量。

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，记住查看反物和产物的浓度。