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February 2018 Issue, Volume 86, No. 2
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Rosalind Franklin's X-ray diffraction patterns of DNA molecules rendered the important clue that DNA has the structure of a double helix. The most famous X-ray photograph, Photo 51, is still printed in most Biology textbooks. We suggest two optical experiments for undergraduates that make this historic achievement comprehensible for students by using macromodels of DNA and visible light to recreate a diffraction pattern similar to Photo 51. In these macromodels, we replace the double helix both mathematically and experimentally with its two-dimensional (flat) projection and explain why this is permissible. Basic optical concepts are used to infer certain well-known characteristics of DNA from the diffraction pattern.
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Guest Editorial
by Andria C. Schwortz. DOI: 10.1119/1.5019345
Papers
by Andrew Marantan, and L. Mahadevan. DOI: 10.1119/1.5003376
by J. Thompson, G. Braun, D. Tierney, L. Wessels, and H. Schmitzer. DOI: 10.1119/1.5020051
by B. Cameron Reed. DOI: 10.1119/1.5009102
by Sa拧a Ziherl, Mojca Cepic, and Jurij Bajc. DOI: 10.1119/1.5009237
by Andr茅ane Bourges, Am茅lie Chardac, Aude Caussarieu, Nicolas Plihon, and Nicolas Taberleta. DOI: 10.1119/1.5009664
by Anthony Allan D. Villanueva. DOI: 10.1119/1.5009921
by Oscar Isaksson, Magnus Karlsteen, Mats Rostedt, and Dag Hanstorp. DOI: 10.1119/1.5007738
Back of the Envelope
by Sanjoy Mahajan. DOI: 10.1119/1.5020066
Physics Education Research
by Abid H. Mujtaba. DOI: 10.1119/1.5008266
Notes and Discussions
by Markus Selmke. DOI: 10.1119/1.5002543
Apparatus and Demonstration Notes
by David T. Chuss. DOI: 10.1119/1.5011731
BOOKS RECEIVED
by Cameron Reed. DOI: 10.1119/1.5020065
91撸色 AJP
General Information, Resources for Authors, Reviewers, and Readers
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