For methionine to stimulate mTOR, it needs to donate a methyl group.

甲硫酸铵要激活雷帕霉素靶蛋白（mTOR）的作用就必须“捐献”出一个甲基组。

So, once methionine donates that methyl group, it becomes homocysteine.

所以，一旦甲硫酸铵“捐献”出甲基组，就会变成巯基丁氨酸。

Small chemical entities called methyl groups attach to stretches of DNA, which affects what sequences are active.

被称为“甲基原子团”的小化学实体附着在DNA片段上，这会对哪些序列是活跃的产生影响。

So if you have too much methionine, you'd have too many methyl groups and you could accelerate aging.

所以，如果甲硫酸铵过多，甲基组就多，甲基组一多就会加速衰老过程。

But, we have an amino acid called glycine that acts as a buffer for too many methyl groups.

但是，人体中有一种名叫甘氨酸的氨基酸，可抵消过量甲基组带来的负面作用。

One is there's a basic skeleton of that amino acid and on top of that, there's what we call a methyl group.

一部分是所谓的基础“骨架”，另一部分则是位于该“骨架”之上的甲基组。

Now what happens when we change out a hydrogen for a methyl group?

现在， 当我们将氢换成甲基时会发生什么？

And the attachment with just one carbon that turns amphetamine into methamphetamine, that's the methyl group.

只有一个碳的连接将苯丙胺转化为甲基苯丙胺， 那就是甲基。

The longest carbon chain is just 3 carbons long, so it's propane with one methyl group sticking off of it.

最长的碳链只有 3 个碳， 所以它是丙烷， 上面有一个甲基。

They're a phenyl group joined by a methyl group instead of just directly.

它们是一个由甲基连接的苯基， 而不是直接连接的。

So for instance, if an octane chain has methyl groups attached with second and fifth carbons, it's called 2,5-dimethyloctane.

因此，例如，如果辛烷链的甲基与第二个和第五个碳相连，则称为 2, 5-二甲基辛烷。

It has two branches, an ethyl group and a methyl group.

它有两个分支， 一个乙基和一个甲基。

The tags, known as methyl groups, act like little switches that can turn on or off particular genes in that DNA.

这些被称为甲基的标签就像一个小开关， 可以打开或关闭 DNA 中的特定基因。

Another example: So this is a benzene with two methyl groups on it.

另一个例子：所以这是一个带有两个甲基的苯。

Except that there's a methyl group sticking off so it's methylbutanoic acid.

除了有一个甲基突出， 所以它是甲基丁酸。

Some of these, like a methyl group, inhibit gene expression by derailing the cellular transcription machinery or causing the DNA to coil more tightly, making it inaccessible.

它们其中的一些，像甲基，抑制基因的表达通过阻碍细胞的转录或导致DNA的盘绕更紧密，使得它们难以看到。

The Prader-Willi genes get turned off when methyl groups get attached to the DNA, a process that happens way back when the mother was making an egg.

DNA甲基化会导致普拉德-威利综合征基因的沉默，这一过程早在母亲产生卵子时就发生了。

The structure we just used had a methyl group on it and an ethyl group on its fifth, it would be 5-ethyl-2-methyloctane.

我们刚刚使用的结构上有一个甲基， 第五个有一个乙基，它是 5-乙基-2-甲基辛烷。

Methyl groups may help maintain the status quo, but if that status quo is interrupted by outside events they can be wiped away and a new lot put in place.

甲基或许可以帮助维持现状，但是如果外来事件打断了它，那么甲基将被移除，新的一批上任。

Now suppose you have more than one of the same size group attached to the same chain, like two methyl groups on the same alkane.

现在假设您有多个相同大小的基团连接到同一条链上，例如同一烷烃上的两个甲基。