Реферат

Реферат на тему James Watson

Работа добавлена на сайт bukvasha.net: 2015-06-04

Поможем написать учебную работу

Если у вас возникли сложности с курсовой, контрольной, дипломной, рефератом, отчетом по практике, научно-исследовательской и любой другой работой - мы готовы помочь.

Предоплата всего

от 25%

Подписываем

договор

Выберите тип работы:

Скидка 25% при заказе до 22.11.2024


James Watson’s The Double Helix: A Review Essay, Research Paper

James Watson’s The Double Helix: A Review

A review of Watson, James D. The Double Helix. New York: Atheneum, 1968.

James Watson’s account of the events that led to the discovery of the

structure of deoxyribose nucleic acid (DNA) is a very witty narrative, and

shines light on the nature of scientists. Watson describes the many key events

that led to the eventual discovery of the structure of DNA in a scientific

manner, while including many experiences in his life that happened at the same

time which really have no great significant impact on the discovery of the DNA

structure.

The Double Helix begins with a brief description of some of the

individuals that played a significant role in the discovery of DNA structure.

Francis Crick is the one individual that may have influenced Watson the most in

the discovery. Crick seemed to be a loud and out spoken man. He never was

afraid to express his opinion or suggestions to others. Watson appreciated

Crick for this outspoken nature, while others could not bear Crick because of

this nature. Maurice Wilkins was a much calmer and quieter man that worked in

London at King’s College. Wilkins was the initial person that excited Watson on

DNA research. Wilkins had an assistant, Rosalind Franklin (also known as Rosy).

Initially, Wilkins thought that Rosy was supposed to be his assistant in

researching the structure of DNA because of her expertise in crystallography;

however, Rosy did not want to be thought of as anybody’s assistant and let her

feelings be known to others. Throughout the book there is a drama between

Wilkins and Rosy, a drama for the struggle of power between the two.

Watson’s “adventure” begins when he receives a grant to leave the United

States and go to Copenhagen to do his postdoctoral work with a biochemist named

Herman Kalckar. Watson found that studying biochemistry was not as exciting as

he hoped it would be; fortunately, he met up with Ole Maaloe, another scientist

doing research on phages (Watson studied phages intensively while in graduate

school). He found himself helping Ole with many of his experiments and soon he

was helping Ole with his experiments more than he was helping Herman with his

experiments. At first, Watson felt like he was deceiving the board of trustees

by not studying the material that the board sent him to study. However, Watson

felt justified because Herman was becoming less and less interested in teaching

Watson because of Herman’s current personal affairs (Herman and his wife decided

to get a divorce). With Herman’s lack of interest in teaching biochemistry,

Watson found himself spending the majority of the day working with Ole on his

experiments.

While in Copenhagen, Herman suggested that Watson go on a spring trip to

the Zoological station at Naples. It was in Naples that Watson first met

Wilkins. It was also in Naples that Watson first became excited about X-ray

work on DNA. The spark that ignited Wilkins’ fire was a small scientific

meeting on the structures of the large molecules found in living cells. Watson

had always been interested in DNA ever since he was a senior in college. Now

that he learned of some new research on how to study DNA, he had the craving to

discover the structure of the mysterious molecule that he believed to be the

“stuff of life”. Watson never had the chance to discuss DNA with Wilkins that

spring; however, that did not kill Watson’s desire to learn about its structure.

Watson’s fire was further kindled by Linus Pauling, an incredibly

intelligent scientist out of Cal Tech. Pauling had partly solved the structure

of proteins. He discovered that proteins have an alpha-helical shape. Watson

thought this was an incredible discovery! He was excited to research and learn

about the DNA structure.

Watson was worried about where he could learn more about DNA and how to

solve X- ray diffraction pictures so the structure of DNA could be understood.

He knew he could not do this at Cal Tech with Pauling because Pauling was too

great a man to waste time with Watson and Wilkins continually put Watson off.

Soon Watson became aware that Cambridge was the place he could get experience to

solve the DNA problem. It was about this time that Watson’s grant was about to

expire. He decided to write Washington and request that his grant be renewed,

continuing his studies in Cambridge rather than Copenhagen. Thinking that

Washington would not deny his request, Watson packed up and went to Cambridge.

He worked several months in Cambridge when finally he received a return letter

from Washington. The letter stated that his grant would not be continued.

Nevertheless, Watson decided to remain in Cambridge and continue his stimulating

intellectual experience.

It was in Cambridge that Watson first met Francis Crick. Here, Watson

discovered the fun of talking to Crick. In addition, Watson was elated that he

found someone in the lab that thought DNA was more important than proteins.

Soon Watson and Crick found themselves having a daily lunch break together

discussing many scientific topics, in particular, the unique aspects of DNA.

As reports came to Watson and Crick about Paulings efforts to discover

the structure of DNA, they began to feel pressure to discover the structure

before Pauling did. However, Watson and Crick were at a disadvantage because

they did not have access to some valuable research done by Wilkins and Rosy.

This did not discourage Watson and Crick. With the limited information they had,

they began to riddle over the possible structures of DNA. So far all the

evidence they had (and also their intuition) indicated that DNA was a helical

structure like proteins with either one, two, or three strands. Pauling was

able to discover the alpha-helix by fiddling with models; by trial and error he

came up with the correct structure. Watson and Crick decided to try model

building as a method of solving the structure of DNA.

Over a period of weeks to months, Watson and Crick fumbled around with

DNA models. All did not go smoothly. One of the difficulties was that Watson

and Crick did not have all the materials available to construct a model with the

inorganic ions like DNA. With some manipulation of on-hand material they were

able to create a model to their liking.

Watson and Crick had constructed a beautiful three chain helix

representing DNA. The next obvious step would be to check the parameters with

Rosy’s quantitative measurements. To their knowledge the model would certainly

fit the general locations of the X-ray reflections. Upon completion, Watson and

Crick were ecstatic about their accomplishment. To be the first to discover the

structure of such an important molecule like DNA was going to make a major

impact in the world.

A phone call was made to Wilkins asking that he come to Cambridge to

view the model and issue his opinion on its validity. The next day both Wilkins

and Rosy came to Cambridge to view the model. Watson and Crick had their

presentations prepared. They planned to dazzle their audience as they explained

how they solved the complexity of the DNA structure. As their discussion went

forth, Wilkins was skeptical on many aspects of the model. Rosy was completely

dissatisfied with the model, especially with the fact that the model had Mg++

ions holding together the phosphate groups of the three-chain model. She noted

that the Mg++ ions would be surrounded by tight shells of water molecules which

contradicted the results she had gained on the water content of DNA molecules

from her experiments.

The rest of the day was spent trying to salvage what little argument

Watson and Crick had. Over lunch was no success, neither did they prevail when

they returned to the lab. Soon the day was over and Wilkins and Rosy returned

to London. When Watson and Crick’s supervisors heard of the failure with the

model, they ruled that no further research would be done at Cambridge on DNA.

For over a year Watson and Crick let DNA alone, only to be pondered upon while

not working on other projects.

That year Watson worked on researching the tobacco mosaic virus (TMV).

A vital component to TMV was the nucleic acid, so it was the perfect front to

mask his continued interest in DNA. Over time and hard work, Watson was able to

show that some parts of TMV were helical in shape and thus decided to return to

work on the structure of DNA.

With more knowledge and expertise the research went forward with passion.

Watson had seen an X-ray picture taken by Rosy that to him gave sure evidence

that DNA was helical. Wilkins data only furthered his conviction. Watson and

Crick were back at it again with a new fervor. They knew that there was a sugar

phosphate backbone to the structure and it was held together somehow by the

nucleic acids (adenine, thymine, cytosine, and guanine). Watson had a hunch

that the shape was going to be a double helix. At first Watson thought the two

backbones were held together by a like-with-like structure (adenine-adenine,

thymine-thymine, etc.) holding the nucleic acids together with a hydrogen bonds.

After about a day Watson realized that a like- with-like structure just was not

possible.

Watson knew that the amounts of adenine always equaled thymine and

amounts of cytosine equaled guanine. With the help of Crick, they tried to

construct a model by pairing adenine with thymine and guanine with cytosine.

This fell together very nicely. After obtaining several opinions on the

validity of their work they placed a call to Wilkins. Wilkins and Rosy came

down and to the surprise of Watson and Crick, Wilkins and Rosy were immediately

pleased with the model. After comparing results and measuring the model they

decided that Wilkins and Rosy would publish a paper at the same time Watson and

Crick published their paper, announcing their discovery.

This was indeed an incredible discovery for the world, especially for

the world of biology. The structure for the “stuff of life” was finally

discovered. Watson and Crick went on to win the Nobel Prize for their work.

Pauling who had worked so hard to discover the structure was not disgruntled by

the fact that someone had beaten him to the discovery, but rather pleased that

the problem was finally solved. Everyone was enthusiastic about the new

discovery.

This was excellent reading. Watson not only told the story of how the

structure of DNA was discovered but he also let us in on the developments of

parts of his personal life. He would speak of how he tried to have dinners at a

school that was teaching young, pretty French girls English. He also spoke much

of his relationship with Crick and Crick’s wife, Odile. He made the book come

alive and science seem more fun, breaking the stereotype of the scientist. I

especially enjoyed how he described Rosy and her firm dedicated feministic

attitude. The reader could feel sympathy for the tribulations Wilkins had to go

through working with her.

The book was an excellent account of the discovery of the structure of

DNA. Throughout the text, Watson mostly eluded to the greatness of others

rather than to his own greatness. Even though he played probably the most

significant part in the discovery of DNA’s structure he gave credit to those

that have inspired him.


1. Реферат на тему Shouls Certain Dog Breeds Be Banned From
2. Реферат Маркетинговые исследования рекламной деятельности
3. Контрольная работа Защита населения и территорий в чрезвычайных ситуациях 3
4. Реферат История,как наука, ее предмет, цель и значение
5. Курсовая Использование наглядных средств обучения на уроках истории
6. Курсовая Налог на добавленную стоимость 2 Порядок исчисления
7. Реферат на тему Steroid Essay Research Paper STEROIDS
8. Реферат Философия искусства
9. Курсовая Конституционно-правовое регулирование, формирование и функционирование системы органов исполните
10. Реферат на тему Gender Stereotypes Essay Research Paper Gender StereotypesToday