英语演讲稿.doc

1、1. Good morning,everyone.Its my pleasure to give this presentation.My name is zhang qing.The first thing I want to do is asking all of you two questions.One is when do you get up?The other is when do you go to bed?Well,I hear that different people have different schedules.But there is a common pheno

2、menon that everyone is sleeping at night and working during the day.Thats what I am planning to cover. 2. My topic is the biological clock is warning you.Yes,Id like to address you on the biological clock.Or more specifically,I would like to tie the subject of the molecular mechanism of controlling

3、circadian rhythms. 3. As we all know,The sunrise makes. The sunset but the rest. This is a phenomenon of the circadian rhythm or the biological clock. 4. But how did this rule come from?How does it work in gene? 5. The origin of this phenomenon is very interesting. A fruit fly that sleeps during the

4、 day ，and during the night howls all the time has caught the attention of scientists. After the further research, it was found that this unique fruit fly is losing circadian rhythm due to the mutation of a period gene in the body. 6. What does the period gene?In other words,How to realize precise re

5、gulation of circadian rhythm in the cell?OK,lets follow my steps. 7. The period gene encodes a protein called PER. The timeless gene encodes a protein called TIM.The double-time gene encodes a protein called DBT. 8. The PER protein will be transferred from the cytoplasm to the nucleus with the help

6、of TIM protein at night.The PER protein will degrade during the day. The process of accumulation and degradation is about 24 hours, which corresponds to peoples day and night.DBT is to slow down the accumulation of PER protein, which controls precise regulation of circadian rhythms. 9. If the proces

7、s of controlling the circadian rhythm is liked as a lock and a key, then open the lock requires two keys, one called the PER protein, controlled by period gene and the other called a TIM protein controlled by timeless gene. The frequency of opening is controlled by the DBT protein encoded by a doubl

8、etime gene. 10. And what is the use of this finding? First, it may heal some of the genetic diseases. Second, it cures insomnia. Third, it could reveal the danger of day and night. When we know the molecular structure of the circadian rhythm, we will have a concrete way to judge that what happens to

9、 the human body when we stay up late. 11. Nowadays,most students have become accustomed to sleep very late. This is very bad to health. Now that the number of postgraduates who have died of fatigue is drastically increasing, we must let the body rest at the right time. Pay attention to the biological clock, who is warning you.To close my speech,I would like to tell one significant thing to you that only with a healthy body can we have better energy to do more researches. 12. Thank you for listening.