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%，可能有腺嘌呤而另有鸟嘌呤。

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

SIRT1的合成取决于种叫NAD（辅酶）的分子，而NAD的合成则取决于种叫NMN的物质。

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

鸟嘌呤总是与胞嘧啶配对，腺嘌呤总是与胸腺嘧啶配对。

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

NAD， 即烟酰腺嘌呤二苷的缩写，是种天然存在于体细胞中的辅酶。

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

这些是（RNA）或脱氧（DNA）的字母。在RNA中，它们分别是胞嘧啶、鸟嘌呤、腺嘌呤和尿嘧啶。

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

在中，它们是腺嘌呤、鸟嘌呤、尿嘧啶和胞嘧啶。

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

所以你有胞嘧啶、鸟嘌呤、腺嘌呤和尿嘧啶。

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

看，DNA 由四种称为“碱基”的不同构件组成：腺嘌呤、胞嘧啶、鸟嘌呤和胸腺嘧啶。

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

如果你看脱氧，我们有的碱基是胞嘧啶、鸟嘌呤、腺嘌呤和胸腺嘧啶。

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种化学成分——腺嘌呤、鸟嘌呤、胞嘧啶和胸腺嘧啶——这4种成分总是以特殊的配对方式排列。

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——由前面我们提到的腺嘌呤、鸟嘌呤、胞嘧吟和胸腺嘧啶4种苷组成。

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（DNA）中，含有胞嘧啶、鸟嘌呤、腺嘌呤和胸腺嘧啶。这里的不同之处在于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。

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的苷由脱氧、磷以及四碱基之组成，分别是腺嘌呤、胞嘧啶、鸟嘌呤与胸腺嘧啶，或简称A、C、G、T。

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（由碳原子和三氢原子组成）附着于腺嘌呤或胞嘧啶上——组成DNA序列的四种主化学成分中的两种，到底附着的是哪种取决于涉及到的基因种类。

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，你有段序列包含胸腺嘧啶（T）、腺嘌呤（A）、胸腺嘧啶（T）、腺嘌呤（A），而在另侧，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。