How Did Watson And Crick Decide To Figure Out The Structure Of Dna
Adam Gruber
9/16/14
Life Science
Professor Nicholas
Double Helix
Watson and Crick decide to use a unique way to figure out the structure of DNA. What other scientist’s method did they decide to use and what was the method?
The method Watson and Crick decided to use to figure out the structure of DNA was x-ray diffraction photography, which was Wilkin’s original method.
Crick sends Watson to a seminar at King’s college where Rosalind Franklin speaks about her work on the structure of DNA. What is Franklin’s approach to solving the structure of DNA? How does her method differ from the approach being used by Watson and Crick?
Rosalind Franklin’s approach to solving the structure of DNA was through crystallographic images. She believed it …show more content…
to be the only method to find the structure of DNA whereas Watson and Crick believed in building models, which she thought were a waste of time.
Watson and Crick invite Wilkins, Franklin and Gosling to come and see their first DNA model.
What three problems does Franklin find wrong with their model?
Three problems Franklin found with Crick and Watson’s model is the location of the phosphate groups should be on the outside but on their model they where on the inside, she believed there needed to be more water than Watson and Crick thought, and she did not believe it was helical.
Erwin Chargaff comes to Cambridge University and Watson and Crick want to meet him to talk about his work on DNA. What did Chargaff discover about the nucleotides in DNA that Watson and Crick later use to help build their model?
Erwin Chargaff discovered that DNA has four different base rings and are found in pairs. He discovered that one base ring is found in the same relative amounts as …show more content…
another.
Linus Pauling publishes a manuscript in which he proposes a structure of DNA. How do Watson and Crick get a hold of Pauling’s manuscript? What are the problems with Pauling’s model?
Watson and Crick get a hold of Pauling’s manuscript through a letter from Linus Pauling to his son Peter Pauling. The problems with Pauling’s model are that he described a three-chain helix with a sugar phosphate backbone at the centre which was unstable. Watson and Crick recognized this as a mistake.
Watson heads to King’s College to show Pauling’s DNA model to Wilkins and Franklin. According to Watson, what happens when he tries to talk to Franklin about Pauling’s paper? \
Franklin becomes angry and argues that there is not a shred of evidence to support a helical structure for DNA.
Watson then meets Wilkins who gives him Photo 51.
What is significant about Photo 51? Who took the x-ray photo?
Photo 51, taken by Raymond Gosling under the supervision of Rosalind Franklin, is significant because it provided essential information in discovering DNA’s structure. The photo identifies the helical nature of the double helix strands.
Watson is having difficulty figuring out how the bases are arranged in the model until Jerry Donohue helps him. What does Donohue tell him that helps Watson figure out how the bases are arranged in the model? Who else’s data does this confirm?
Donahue tells Watson that he is playing with the wrong structures for guanine and thymine. He proposes that Watson put the bases in the middle and the phosphates outside making each strand a mirror image of each other. This finding also confirms Erwin Chargiff’s data.
Watson and Crick build another model of DNA and again they invite Wilkins, Franklin and Gosling to see it. In your own words, describe the structure of DNA.
DNA is a double helix made up of two complimentary intertwined strands held together by hydrogen bonds between the base pairs. The base pairs are located in the center of the helix, while the outer strands are made up of glucose and phosphorous
molecules.
Watson has been criticized for his depiction of Franklin in The Double Helix, especially since she was dead by the time the book was published. What are your impressions of Franklin based on your reading of the book? Give specific examples from the book to back up your opinion.
Watson’s depiction of Franklin in The Double Helix is not a positive one. She is made out to be highly opinionated, difficult, and outspoken. However her involvement in the discovery of DNA was a critical one and for that, I believe, deserves respect from Watson, which he does not seem to give her in his book. I believe Watson was sexist and discredited her work just for being a woman. He stated that she must “be put in her place given her belligerent moods”(17). Franklin’s attitudes and behaviors were a direct result of working in a male dominated field at a time when women were not expected to work outside of the home, especially in science. I believe she acted in way that demanded respect to put herself on the level of her colleagues.
9/16/14
Life Science
Professor Nicholas
Double Helix
Watson and Crick decide to use a unique way to figure out the structure of DNA. What other scientist’s method did they decide to use and what was the method?
The method Watson and Crick decided to use to figure out the structure of DNA was x-ray diffraction photography, which was Wilkin’s original method.
Crick sends Watson to a seminar at King’s college where Rosalind Franklin speaks about her work on the structure of DNA. What is Franklin’s approach to solving the structure of DNA? How does her method differ from the approach being used by Watson and Crick?
Rosalind Franklin’s approach to solving the structure of DNA was through crystallographic images. She believed it …show more content…
to be the only method to find the structure of DNA whereas Watson and Crick believed in building models, which she thought were a waste of time.
Watson and Crick invite Wilkins, Franklin and Gosling to come and see their first DNA model.
What three problems does Franklin find wrong with their model?
Three problems Franklin found with Crick and Watson’s model is the location of the phosphate groups should be on the outside but on their model they where on the inside, she believed there needed to be more water than Watson and Crick thought, and she did not believe it was helical.
Erwin Chargaff comes to Cambridge University and Watson and Crick want to meet him to talk about his work on DNA. What did Chargaff discover about the nucleotides in DNA that Watson and Crick later use to help build their model?
Erwin Chargaff discovered that DNA has four different base rings and are found in pairs. He discovered that one base ring is found in the same relative amounts as …show more content…
another.
Linus Pauling publishes a manuscript in which he proposes a structure of DNA. How do Watson and Crick get a hold of Pauling’s manuscript? What are the problems with Pauling’s model?
Watson and Crick get a hold of Pauling’s manuscript through a letter from Linus Pauling to his son Peter Pauling. The problems with Pauling’s model are that he described a three-chain helix with a sugar phosphate backbone at the centre which was unstable. Watson and Crick recognized this as a mistake.
Watson heads to King’s College to show Pauling’s DNA model to Wilkins and Franklin. According to Watson, what happens when he tries to talk to Franklin about Pauling’s paper? \
Franklin becomes angry and argues that there is not a shred of evidence to support a helical structure for DNA.
Watson then meets Wilkins who gives him Photo 51.
What is significant about Photo 51? Who took the x-ray photo?
Photo 51, taken by Raymond Gosling under the supervision of Rosalind Franklin, is significant because it provided essential information in discovering DNA’s structure. The photo identifies the helical nature of the double helix strands.
Watson is having difficulty figuring out how the bases are arranged in the model until Jerry Donohue helps him. What does Donohue tell him that helps Watson figure out how the bases are arranged in the model? Who else’s data does this confirm?
Donahue tells Watson that he is playing with the wrong structures for guanine and thymine. He proposes that Watson put the bases in the middle and the phosphates outside making each strand a mirror image of each other. This finding also confirms Erwin Chargiff’s data.
Watson and Crick build another model of DNA and again they invite Wilkins, Franklin and Gosling to see it. In your own words, describe the structure of DNA.
DNA is a double helix made up of two complimentary intertwined strands held together by hydrogen bonds between the base pairs. The base pairs are located in the center of the helix, while the outer strands are made up of glucose and phosphorous
molecules.
Watson has been criticized for his depiction of Franklin in The Double Helix, especially since she was dead by the time the book was published. What are your impressions of Franklin based on your reading of the book? Give specific examples from the book to back up your opinion.
Watson’s depiction of Franklin in The Double Helix is not a positive one. She is made out to be highly opinionated, difficult, and outspoken. However her involvement in the discovery of DNA was a critical one and for that, I believe, deserves respect from Watson, which he does not seem to give her in his book. I believe Watson was sexist and discredited her work just for being a woman. He stated that she must “be put in her place given her belligerent moods”(17). Franklin’s attitudes and behaviors were a direct result of working in a male dominated field at a time when women were not expected to work outside of the home, especially in science. I believe she acted in way that demanded respect to put herself on the level of her colleagues.