時(shí)差N小時(shí):基因"食譜"(上)

　　To stay healthy, your cells must continuouslyperform a wide variety of chemical tasks. Your DNAgenes, in the nucleus of every cell, helporchestrate this activity. A cell uses its genes as akind of biochemical cookbook: whenever it has todo anything, a cell looks up the recipe in its DNA. Itthen uses this recipe to cook up whatever proteins itneeds to get the job done. Your cells are hard atwork right now, creating thousands of tailor madeproteins for thousands of different biochemical jobs.Sometimes, however, things can go wrong. When avirus attacks, it injects its own DNA into one of your cells. Like your own genes, the viral DNAcontains recipes. Unfortunately, these recipes are only good for making new viruses.

　　為了保持健康，你的細(xì)胞必須不斷地進(jìn)行各種各樣的化學(xué)反應(yīng)。你的DNA基因，存在于每一個(gè)細(xì)胞的細(xì)胞核，會(huì)幫助協(xié)調(diào)這項(xiàng)活動(dòng)。細(xì)胞用它的基因作為一種生化食譜：無論何時(shí)細(xì)胞在工作的時(shí)候，它都要在DNA查詢配方。然后，它使用這個(gè)配方來烹煮蛋白質(zhì)所需的物質(zhì)，從而完成化學(xué)反應(yīng)。此刻你的細(xì)胞都在努力工作，創(chuàng)造數(shù)以千計(jì)由蛋白質(zhì)形成的“裁縫”來完成數(shù)千項(xiàng)不同的生化反應(yīng)。然而，有時(shí)候，事情會(huì)出差錯(cuò)。當(dāng)病毒攻擊時(shí)，它將自身的DNA注入到你的細(xì)胞中。像你自己的基因一樣，病毒的DNA也包含有食譜。不幸的是，這些食譜只對(duì)產(chǎn)生新的病毒有利。