An extensive review of the investigations made hitherto on the cellular endogenous electromagnetism, how is generated and sensed.
" .. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic fi eld can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electro- magnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fi elds and discuss experimental evidence on electromagnetic cellular inter- actions in the modern scienti fi c literature. Although small, it is continuously accumulating."
It's viewed that EMF are an integral part of the biological systems and are part of purposeful processes.
The authors begin describing some of the processes that can generate EMF on cells; on neurons, membrane depolarization (a neuron firing at several hundred Hz) generates oscillations of electric charges with higher harmonics, creating an EMF with a frequency up to 10 kHz, for all types of cells there is described another EMF generation mechanism: coherent longitudinal vibrations of electrically polar structures (proposed initially by Fröhlich), where majority of the proteins are electrically polar structures. In this model, the structures reach a steady-state of non-linear vibrations (caused by a strong static electric field) with energy stored in a highly ordered fashion. Fröhlich also proposed the existence of a selective resonant interaction of similar frequencies of biomolecular EMFs between two systems. There are various experimental findings and model constructions that take in consideration the existence of this kind of vibrations (see section ) and apart from the membrane as a source for this phenomenon (the original proposition) now microtubules (MT) are taking much attention as a candidate for this EMF generation method (section ) where the static electric field of mitochondria cause no-linearity of MT vibrations. Membrane in all type of cells can be also source of EMF; mechanic resonance at cell membranes (both perpendicular and parallel to membrane surface), deformations and asymmetries of polar cellular membrane as a mechanism for generation of acousto-electrical waves whose EM radiative component depends on deviation from the healthy state, etc. Other theories propose that cellular EMFs can be generated by the coupling of oscillating chemical reactions to physically mobile ions.
They continue describing as possible sources of electromagnetic field other systems related, this time, to the generation of Ultraweak Photon Emissions (UPE, or also Biophotons) (there are various sections of this web dedicated to this phenomenon). There are various experiments that propose the mitochondria as a source of all kind of biophotons (ultraviolet, visible and near infrared) as is a source of ROS production (but is not the only one, in this web are pointed out other possible sources . The most probably is that there are various sources in different wavelengths and have different functions , and for example UV biophotons are probably guided through microtubules  meanwhile water can have a prominent function also in generation of those emissions ), the authors of the paper pointed out also (as I mentioned) water as a possible source of those EMF. Also there is a proposition for the possibility of photo-emission from collective molecular interactions such as the relaxation of superhelical DNA, indeed Popp et al. proposed DNA as the main source for UPE and also suggested that DNA is suitable as a photon storage system due to its spatial conformation. The authors propose:
" It is generally accepted that the main sources of cellular UPE are excited molecules such as reactive oxygen species (ROS), which can release their energy in rather random chemical reactions as photons. However, ROS can also provide energy to macromolecular structures which can store the energy and release it in a more coherent fashion."
They explain how some scientists treat to make a possible connection between generation KHz-GHz EMF (by the vibration of electrical polar structures) and UPE (by the electronic excitation of molecules).
This review continues with evidences of how cells are affected by all kind of electromagnetic radiations, so there must be some kind of possible targets in the cells [as a example of how this is a real fact, you can find extensive lists with links to the latest experiments and papers of applied electromagnetic fields in research of both intentional  (experimentally and therapeutically) and not intentional  (electromagnetic contamination) effects that cause on biological systems]
Those effect are provoked by low intensity electromagnetic fields so they must somewhat surpass the naturally occurring thermal energy (the kT problem) but as they explain in the text this is a problem only if the system is near-equilibrium and is not applicable to organisms. In the latest the thermalization time may be significantly greater than in systems in thermal equilibrium. Thus, it is not surprising that EMFs can induce a significant change in energy in some degrees of freedom before dissipation or redistribution of the energy.
They mention Ion cyclotron resonance theory by Liboff and also that the Fröhlich modes mentioned previously are possible target of external EMF. And also water (by generation of intrinsic resonant frequencies by water clusters) is a possible candidate to effects of 50-70 GHz radiation fields.
They describes three mechanisms through which EMFs can be extracted from a noisy background by biological systems. And also describe models where membrane macromolecules and membrane-bound enzymes and pumps are considered as receptors for EMF, or where simple biomolecules are the receptors. Another theory is that EMF affect electron transport in DNA interacting directly with electrons and changing the biosynthesis of proteins. Finally among the interactions into the EMF in the visible range they describe the Cosic model of Resonant Recognition where charge moving through a protein backbone can produce EMF radiation or absorption with spectral characteristics corresponding to the potential energy profile of the protein (see section  for more on this topic).
Lastly it describes more experimental results, in this case of EMF interactions in the range of visible and ultraviolet wavelengths between cells.
 Karbowski, L. M., & Persinger, M. A. (2015). Variable viscosity of water as the controlling factor in energetic quantities that control living systems: physicochemical and astronomical interactions. International Letters of Chemistry. Physics and Astronomy, 4, 1-9.
Last modified on 15-Mar-16