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17. Absorption spectra of L-tyrosine in acidic (continuous line) and basic (dotted line) medium was estimated and plotted on a graph as depicted below: Following interpretations were made: A. Change […]

16. The above figure shows the fluorescence emission spectra of three different proteins; Protein (X), Protein (Y), and Protein (Z) excited at 280 nm. Which one of the following statements […]

15. The emission maximum of tryptophan fluorescence in a protein is ~335 nm. This suggests that tryptophan (1) is in a hydrophobic environment. (2) occurs in a helical segment. (3) […]

14. Emission maximum of a fluorophore is shifted to longer wavelength when compared to the wavelength of excitation. What is the reason? (1) Non-radiative loss of excitation energy (2) Partial […]

13. A solution contains NADH and NAD+, BOTH AT 0.1 mM concentration. If NADH has a molar extinction coefficient of 6220 and that of NAD+ is negligible, the optical density […]

12. The values of molar absorption coefficient (ε) of Trp and Tyr at 240 nm and 280 nm are the following: Wavelength (nm) εTyr (M−1 cm−1) εTrp (M−1 cm−1) 240 […]

11. A protein contains 2 Trp and 4 Tyr residues. The molecular mass of the protein is 17000 Da and that of Trp and Tyr are 204 and 180 Da, […]