What is needed for photosynthesis to take place? Sophie.

光合作用反应物什么？苏菲。

If the environment being spread through is an animal embryo and the reagents are hormones that trigger the differentiation of the body's pigment-producing cells, the upshot is a distinct pattern of pigmentation.

如果扩散环境动物胚胎，反应物诱发身体色素产生细胞差异荷尔蒙，那么结果就斑驳颜色。

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.

答案一系列无休止反应，这些反应致力于做两件至关重要且完全矛情：一组化学反应会破坏你给它们反应物，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?

，叶子要如何防止不必要入侵者（如细菌）进入并阻止重要反应物逸出？

Reactants become products and that's that.

反应物变成产物，仅此而已。

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

下面海绵状中叶，它们之间有足够空间供反应物移动通过。

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.

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

And so what are the reactants here?

这里反应物什么？

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

因此，它把某些反应物转化为产物。

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

这儿有我另一种反应物。

But what was it about the reagent that revealed the ink?

什么反应物揭示了墨水？

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应逆向速率定律，它形式会与正向一样，使用产物初始浓度而不反应物初始浓度。

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产物， 那么它会反应向右移动；如果它倾向于形成更多反应物， 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.

反应焓变等于产物标准生成焓之和减去反应物标准生成焓之和。

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.

想象一个反应 A 加上 B 生成 C 加上 D。小写字母代表反应物和生成物系数。

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

你投入反应物越多，它们相互碰撞并发生反应机会就越大。

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物，或者测量正在被消耗反应物量。

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，记住查看反应物和产物浓度。

So over here on the left-hand side we have the reactants.

所以在左边我们有反应物。

Notice that only the reactants are used for this not the products.

注意这里只使用了反应物，而不生成物。