BioPHYSICAL chemistry
Determination of secondary structure using circular dichroism Chiral molecules can be distinguished based upon their inter- acti ...
bonds. Bond rotation through an angle φis modeled as having a periodic dependence on the angle that corresponds to the different ...
286 PART 2 QUANTUM MECHANICS AND SPECTROSCOPY If the potential expression is subjected to a simple least-squares approach, then ...
atoms from moving beyond realistic bond distances and angles. For refinement of X-ray data, the positions are also adjusted to a ...
final fold. Two general interactions influence the intermediate state. The overall globular shape reflects the sequestering of h ...
Due to the complexity of proteins, challenges remain in the accurate modeling of protein interactions and their use in protein d ...
13.14 How is the secondary structure influenced by the presence of hydrogen bonds? 13.15 What happens when a charge is generated ...
The nature of light What is light? Michael Faraday and James Maxwell realized in the 1800s that light is an electromagnetic wave ...
Due to the quantization of energy (Chapter 9), the amount of energy in a wave of light is proportional to its frequency, with hi ...
CHAPTER 14 OPTICAL SPECTROSCOPY 293 The Beer–Lambert law The amount of light that is absorbed by a sample depends upon several f ...
Converting the natural logarithm to base 10 logarithm gives: (14.7) where the proportionality constant ε, known as the molar abs ...
a reference sample cell that contains everything that is in the sample to be measured, except for the molecules being measured. ...
may be possible to identify the relative amount of each state if they have different spectra. If the spectrum of each pure compo ...
(14.15) where E 2 andE 1 are the energies of the states 2 and 1 respec- tively. Correspondingly, light is emitted when an electr ...
be a photon present in the initial state. The presence of this photon inter- acts with an electron and induces the transition of ...
CHAPTER 14 OPTICAL SPECTROSCOPY 299 We can then write: (db14.4) This term has the advantage that it can be related directly to t ...
Albert Einstein used statistical mechanics (Chapter 8) to show that: (14.23) Thus the rate of stimulated absorption and stimulat ...
is to create a population inversion of level 3 compared to level 4. Rather than trying to create this directly, two new states, ...
According to the properties of spherical harmonics: (14.26) Complete integration of these terms will of course give the exact di ...
The relationship between emission and absorption spectra The key features of absorbance spectra are the wavelength of the peak o ...
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