This attaches methyl groups (a carbon atom and three hydrogens) to either adenine or cytosine, two of the four chemical bases that form the alphabet of DNA, depending on the gene involved.

该作用可以让甲基（由一碳原子和三氢原子组成）附着于呤或胞嘧啶上——组成DNA序列的化学成中的两，到底附着的是哪取决于涉及到的基因类。

Nucleotides of DNA are made out of a sugar deoxyribose, a phosphate, and one of the four nuclear bases: adenine, cytosine, guanine, and thymine or A, C, G, T for short.

DNA的核苷酸由脱氧核糖、磷酸以及核碱基之一组成，别是呤、胞嘧啶、鸟呤与胸嘧啶，或简称A、C、G、T。

It was known that DNA had four chemical components - called adenine, guanine, cytosine, and thiamine - and that these paired up in particular ways.

当时已经知道，DNA含有4化学成——呤、鸟呤、胞嘧啶和胸嘧啶——这4成总是以特殊的配对方式排列。

SIRT1 depends on a molecule called NAD (Nicotinamide adenine dinucleotide), and NAD, in turn, depends on the substance called NMN.

SIRT1的合成取决于一叫NAD（辅酶）的子，而NAD的合成则取决于一叫NMN的物质。

But for the remaining .1%, one person might have an adenine where another person has a guanine.

但对于剩下的0.1%，一人可能有呤而另一人有鸟呤。

The bases - the letters of the genetic alphabet - consist of the four nucleotides mentioned a page or two back: adenine, thiamine, guanine, and cytosine.

碱基——基因子母表中的字母——由前面我们提到的呤、鸟呤、胞嘧吟和胸嘧啶4核苷酸组成。

Guanine always pairs with cytosine and adenine always pairs with thymine.

鸟呤总是与胞嘧啶配对，呤总是与胸嘧啶配对。

NAD, short for nicotinamide adenine dinucleotide, is a coenzyme that occurs naturally in human cells.

NAD， 即烟酰胺呤二核苷酸的缩写，是一天然存在于人体细胞中的辅酶。

See, DNA is made up of four different building blocks called " bases" : adenine, cytosine, guanine, and thymine.

看，DNA 由称为“碱基”的不同构件组成：呤、胞嘧啶、鸟呤和胸嘧啶。

If you look at DNA the bases that we have are cytosine, guanine, adenine and thymine.

如果你看脱氧核糖核酸，我们有的碱基是胞嘧啶、鸟呤、呤和胸嘧啶。

These are the letters of RNA or the letters of DNA. Cytosine, guanine, adenine and uracil in RNA.

这些是核糖核酸（RNA）或脱氧核糖核酸（DNA）的字母。在RNA中，它们别是胞嘧啶、鸟呤、呤和尿嘧啶。

So you've got cytosine, guanine, adenine and uracil.

所以你有胞嘧啶、鸟呤、呤和尿嘧啶。

Cytosine, guanine, adenine and thymine in DNA. The other difference here is in DNA. We actually have a double helix so those attach together.

在脱氧核糖核酸（DNA）中，含有胞嘧啶、鸟呤、呤和胸嘧啶。这里的一不同之处在于DNA，我们实际上拥有的是双螺旋结构，因此这些碱基对会相互配对连接。

And so in RNA, it's adenine, guanine, uracil and cytosine.

在核糖核酸中，它们是呤、鸟呤、尿嘧啶和胞嘧啶。

And the reason it's called a TATA Box is you have a thiamine adenine thiamine adenine and on the other side you'd have TATA backwards complimentary to that.

它被称为TATA框的原因是，你有一段序列包含胸嘧啶（T）、呤（A）、胸嘧啶（T）、呤（A），而在另一侧，你会看到与这段序列互补的反向序列，即TATA的反向互补序列。