我家少爷画地为牢,很怕写作文,总说自己写得不好。
上次被我逼了去参加学校作文比赛的选拔。考试过程是在45分钟内,每人写一篇作文,题目是"写最近一次让你流泪或者快要流泪的事情"。少爷回来说,他花了很长的时间考虑写什么,等他好不容易想好了,刚刚写了个开头,交卷时间就到了。我说,没关系,你没经验,下次不要花这么长的时间酝酿,快点开写。再问,那你到底写了什么让你伤心的事情?人家回答说,我写我的狗死了。什么???孩子啊,我们家从来没有养过狗,你,你这不是胡编乱造吗?
少爷气愤地说,妈妈,你不觉得我的生活太平淡了吗?我实在没有什么有戏剧性的故事可以写啊。
上个周末,少爷哼哼叽叽不肯去中文学校。我说好吧,不过你得在家写一篇作文。他问写什么,我说写写我们的春假吧。少爷面露痛苦,那有什么可写的。问,我可不可以写我感兴趣的内容,比如telomerose?我说可以,于是他就写了这么一篇。
Telomerase: The Fountain Of Youth
Since the beginning of time, humans have yearned to subvert the natural course of time, with stories such as Ponce de Leon’s Fountain of Youth, which would grant eternal life to those who bathed in it’s waters. There are other stories of substances that would bring immortality, such as an Elixir of Life, and substances like jade and cinnabar. We still can’t promise eternal life. But with the miracle of modern science, we now have a substance, telomerase, that can come close.
Telomerase is a ribonucleoprotein, or, more simply, an enzyme. It is a biocatalyst that affects metabolic reactions in the body. Like all enzymes, telomerase has a purpose. It’s purpose is to regenerate telomeres. But what do telomeres do? Every day, cells in the body are created and destroyed. This happens through processes called meiosis and mitosis, where a cell splits into two new cells. The chromosomes are replicated into each new cell. At the end of the chromosomes are telomeres. They act as caps, preventing the chromosomes from being damaged or flawed. But when the human body runs out of telomeres and telomerase to reproduce telomeres, organs fall into disrepair and shrivel, other organs start to fail, the body becomes infertile, and eventually dies. This is known as aging.
With a surplus of telomerase, aging could theoretically slow, stop, or even reverse. In 1961, Leonard Hayflick first noticed that a cell can only reproduce between 40 and 60 times. This is known as the Hayflick Limit. Research in telomere shortening started in 1973 by a Soviet biologist, Alexey Olovnikov, who connected telomeres and aging. In 1984, Carol Greider and Elizabeth Blackburn discovered telomerase, along with Jack Szostak. However, scientists quickly realized that aging was not a direct process, but had many deciding factors. Telomerase was not as crucial as they had thought.
Since the discovery of telomerase, many experiments concerning it have been conducted. Mice born without telomerase quickly aged and gained age related disabilities. However, when supplied with telomerase, they miraculously became healthy again. Even if telomerase therapy was used on humans, many are worried that telomerase could excite tumors. In fact, telomerase is what makes cancer so deadly. Others argue that telomerase would eliminate DNA damage, stopping cancer altogether. With our limited technology, we are yet to find out who’s right.
Even though telomerase is not reliable enough to test on humans, we can lengthen telomeres with simple activities such as exercise. Just taking a walk every now and then can increase a person’s lifespan, and make them healthier to boot. Although miracle substances like a magic fountain may never exist, the mysteries of telomerase are sure to be unraveled soon.
怎样教初中生写作文我不太懂,对他写的具体内容也不详,贴上来求建议求引玉。
以前的:便秘作文