How does the structure of DNA identified by Watson and Crick differ from the model previously proposed by Linus Pauling and others?
Question
How does the structure of DNA identified by Watson and Crick differ from the model previously proposed by Linus Pauling and others?
Solution
The structure of DNA identified by James Watson and Francis Crick significantly differs from the model previously proposed by Linus Pauling and others. Here's how:
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Shape: Pauling proposed a triple helix model for DNA, where three chains of DNA were coiled around each other. Watson and Crick, on the other hand, proposed a double helix structure, where two chains of DNA wind around each other.
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Location of Bases: In Pauling's model, the bases were on the outside of the DNA molecule, and the phosphates were in the core. However, Watson and Crick's model proposed that the bases were in the core of the molecule, and the phosphates were on the outside.
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Base Pairing: Pauling's model did not include specific base pairing, while Watson and Crick's model proposed that adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). This base pairing is crucial for DNA replication.
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Hydrogen Bonding: Watson and Crick's model also included hydrogen bonding between the bases, which was not part of Pauling's model. These hydrogen bonds help to stabilize the DNA molecule.
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Directionality: In Watson and Crick's model, the two strands of DNA run in opposite directions (antiparallel), which was not the case in Pauling's model.
In conclusion, Watson and Crick's model of DNA was more accurate and detailed, and it provided a mechanism for DNA replication, which Pauling's model did not.
Similar Questions
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9. Watson and Crick used scientific reasoning, their knowledge of biochemistry, and the research of otherscientists to make one of the most important scientific claims of their time: DNA is a double helix withstrands running in opposite directions. Between these strands, A pairs with T, and C pairs with G.Complete the table on the following page to explain the evidence that Watson and Crick used to support thisclaim:DNA is a double helix with strands running in opposite directions. Between these strands, A pairs withT, and C pairs with G.Film ActivityStudent HandoutThe Double HelixDNA & RNA Updated February 2020www.BioInteractive.org Page 4 of 4Evidence: (List three pieces of evidence for the claim. Name the scientists who were responsible foreach piece.)Reasoning: (In full sentences, explain how each piece of evidence supports the claim.)10. Even before the structure of DNA was known, studies indicated that the genetic material must have thefollowing properties:• be able to store information• be consistently replicated between generations• be able to allow for changes, and thus evolution, to occurExplain how the structure of DNA gives it these three properties. Write one or two sentences per property
Watson and Crick proposed the model for the 3D structure of DNA. Within this model: Group of answer choicesthe distance between the two strands of DNA is 4 nm.the two strands of DNA are held together by covalent bonds.the two strands of DNA run in the same 5’ → 3’ direction.ten bases are found in each turn of the helix.
In the Watson-Crick model for the DNA double helix, which of the following is true?Group of answer choicesThe strands are held together by peptide bondsThe strands are held together by ionic bondsThe DNA strands are parallelThe DNA strands are anti-parallel
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