telomarase端粒和端粒酶

• The assumption is that even these DNA doesn’t make up any of the genes, they must serve some other purpose. Anyway, if we examine these ends of these DNA, we will find a sequence of DNA at each end of every human chromosome, called a telomere. Now a telomere is a highly repetitious and genetically meaningless sequence of DNA. But it does have any important purpose; it is sort of like the plastic tip on each end of shoelace. It doesn't help you tie your shoes, but that little plastic tip keeps the rest of the shoelace. Well, the telomere at the end of chromosomes seems to do the same thing--- protect the genetically functional parts of the chromosome from being damaged. • 即使是这些 DNA不组成任何基因，它必须服务于它的一些其 他目的。不管怎么说，如果我们检查这些 DNA的两端，会发 现在每个人类染色体上的DNA序列，叫做端粒DNA序列。端 粒是高度重复的基因毫无意义的DNA序列。但它确实有任何 重要的目的；这就有点像鞋带两端末端的塑料。这并不帮你 系鞋带，但是那小小的塑料末端保留其余的鞋带。嗯，染色 体末端的端粒似乎做相同的事情——保护基因染色体的基因 功能免受破坏。
• Every time the chromosome divides, pieces of the ends of the chromosome, the telomere, get broken off. So after each division, the telomere gets shorter and pieces of the genes get broken off the chromosomes. So the chromosome is now losing important genetically information. But as long as the telomeres are at certain length, they keep this from happening. But when we analyze the cells chemically, we find something very interesting, a chemical in them, an enzyme called telomerase. As bits of the telomere break off from the end of chromosome, the telomerase can rebuild it and help protect the telomere that the chromosome loses. • 每一次染色体分裂时，每次一个细胞分裂成两个。染色体端粒 末端脱离。所以在每次分裂后, 端粒变短，基因片段脱离染色 体。所以，染色体现在失去重要基因信息。但是，只要端粒超 过一定的长度，他们阻止这一切发生。但当我们从化学角度分 析细胞我们发现一些很有趣的东西，一种化学物质叫做端粒酶。 当端粒从染色体末端脱落，端粒酶可以重建它，并且保护染色 体丢失的端粒。
• Someday we may be able to keep cells alive and reproduce itself forever through the use of telomerase. And in the future we may have virtually immortal nerve cells and skin cells because these chemical can keep the telomere on the ends of chromosomes from getting any shorter.
• 总有一天我们可以使任何一个细胞通过端粒酶保持细胞的 活力运作并自身复制。在未来，我们可能有永不衰亡的神 经细胞和皮肤细胞，因为这些化学物质可以防止染色体两 端的端粒变短。
——节选自TPO12 listening part lecture1
Байду номын сангаас
• OK, you know that all of persons’ genetic information is contained on very long pieces of DNA called chromosomes. And if you stretch them out, you will find they contain certain genes, certain sequences of DNA that help to determine how the cells of the body will develop. When researchers look really carefully at the DNA in chromosomes, they were amazed to find that only a fraction of it, maybe 20-30%, converts into meaningful genetic information. If you took away all the DNA that codes for genes, you still have maybe 70% of the DNA left over. That’s the socalled junk DNA. • 好吧，你知道所有的人的遗传信息都包含在很长一段叫作染 色体的 DNA 片断。如果你伸直，你会发现它们包含某些特 定的基因，某些 DNA 序列，以帮助确定身体的细胞会如何 发展。当研究人员真的仔细看看染色体中的 DNA，他们惊讶 只有一小部分，大约20-30%，转换成有意义的遗传信息。如 果你带走了所有的 DNA 编码的基因，你仍有可能 70%的遗 留下来的 DNA。这是所谓的垃圾 DNA。