Noise as a source of information about dynamical properties of biological macromolecules
✍ Scribed by Izchak Z. Steinberg
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1987
- Tongue
- English
- Weight
- 894 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
The time course of a noise signal is not completely random, since it is coupled to the characteristic dynamical behavior of the physical system that produces the noise. The statistical properties of the noise may thus be very informative about the properties of the noise-generating system. The use of the autocorrelation function, of modified autocorrelation functions that show directionality with respect to the time axis, and of probability density-distribution functions of intervals in noise traces are discussed. Thus, by labeling specific points on polymer chain molecules by suitable chormophores between which excitation energy transfer may occur and by analyzing the autocorrelation function of the fluctuations in the emitted fluorescence under steady illumination, one may characterize the internal dynamics of the polymer molecules. It is also shown that the presence or absence of time directionality in noise traces, as tested with the help of some of the above-mentioned statistical functions, may demonstrate whether the noisegenerating system is at thermodynamic equilibrium or whether irreversible processes are coupled to the dynamic changes that produce the noise signals.