Conjugated cyanine dyes are commonly used to label proteins and nucleic acid for spectroscopic applications. Cy3- and Cy5-labeled DNA oligomers, given below, have different emission spectra as presented in the below figure, 1.0 0.8 Суз 0.6 3 0.4 N° 4 0.2- A Су5 0.0 500 550 600 650 700 750 WAVELENGTH ( nm) Which of the following statements is (are) true? (I) The A spectrum likely corresponds to a Cy3-labeled DNA oligomer. (II) The B spectrum likely corresponds to a Cy3-labeled DNA oligomer. (III) The energy gap between the HOMO and the LUMO levels for Cy3 is larger than that of Cy5. (IV) For Cy3 and Cy5, the electron is excited from the n= 5 energy level. A) I only B) I and II C) I and III D) II and IV |E) II only wu s09 wu IS FLUORESCENCE INTENSITY

Conjugated cyanine dyes are commonly used to label proteins and nucleic acid for spectroscopic applications. Cy3- and Cy5-labeled DNA oligomers, given below, have different emission spectra as presented in the below figure, 1.0 0.8 Суз 0.6 3 0.4 N° 4 0.2- A Су5 0.0 500 550 600 650 700 750 WAVELENGTH ( nm) Which of the following statements is (are) true? (I) The A spectrum likely corresponds to a Cy3-labeled DNA oligomer. (II) The B spectrum likely corresponds to a Cy3-labeled DNA oligomer. (III) The energy gap between the HOMO and the LUMO levels for Cy3 is larger than that of Cy5. (IV) For Cy3 and Cy5, the electron is excited from the n= 5 energy level. A) I only B) I and II C) I and III D) II and IV |E) II only wu s09 wu IS FLUORESCENCE INTENSITY

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter20: Dienes, Conjugated Systems, And Pericyclic Reactions

Section20.3: Uv-visible Spectroscopy

Problem 20.5P

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