Are mitochondria the natural cellular light sources?

[See ref 18 ]

What are the natural emitters of pulsating infrared signals in the world of cells? We know of no inanimate object around cells that emits pulses of near infrared light. Therefore, we need to look inside cells for them. The best candidates appear to be the mitochondria because they contain the vast majority of porphyrin (heme-)containing proteins in tissue cells, namely the cytochromes. In phase contrast microscopy they are only visible in the thinner parts of the cell body (see below).

However, as shown in the fluorescent micrograph below, each cell contains a large number of them.

Fluorescence micrograph of rhodamine stained live mitochondria of a single cell. Each bright, squiggly line is a mitochondrion. The nucleus does not contain mitochondria and, therefore, appears as a dark circle in the middle of the cell.

The possible role of heme-related molecules in the reception and emission of near infrared light

The heme group is derived from the porphyrin molecules which is essentially a network of 36 conjugated bonds arranged in a flat disk.

Basic molecular structure of porphyrins. The side chains are not specified.
The center of the heme group and other related molecules contains a metal ion. Such a system of many conjugated bonds may generate energy states which have properties somewhere in between the discrete energy levels of single atoms and the continuous energy band structure of (infinite) solid state crystals. The charge of the metal ion is able to fine-tune the energy levels. These energy states may lie very close to each other and yet not allow transitions between them for reasons of the conservation of momentum and spin. Thus they may accumulate and store small packages of energy such as infrared photons well protected from the ubiquitous thermal chaos of the cellular world until a very specific trigger discharges them. The discharge may release photons of higher energy than the single photons that build up the charge and it may also generate sudden electrical conductivity of the molecule because electrons moved into the higher energy levels that are comparable to the conduction bands of crystals. In other words the porphyrin molecule may serve as a powerful accumulation and amplification mechanism for the small energy of the individually absorbed photons.

Chlorophylls and cytochromes as models for the absorbers and emittors of near infrared light.

All chlorophylls contain the heme group as the chromophore which absorbs the light energy used for photosynthesis. Some of the chlorophylls such as bacteria-chlorophyll absorb at the same near infrared wavelength which most attracctive for the tissue cells in our experiments. Therefore, bacteriochlorophyll may be considered as a model for the unknown pigment molecules in the centrioles of the light sensitive tissue cells that absorb the near infrared light.

Heme proteins may also serve as models for the unknown emitter substances of the pulsating infrared light because there is no principal reason why the quantum-mechanical absorption mechanism could not also be an emission mechanism. For example, I have shown recently that bacteriochlorophyll is able to fluoresce in the near infrared range [See ref 18]. As mentioned above,mitochondria contain practically all the heme proteins of tissue cells. Therefore, they appear to be excellent candidates for near infrared emitters of cells. It is also likely that they would emit the light in pulses whenever they discharge a load of ATP molecules that they have synthesized in the course of their normal function, namely oxidative phosphorylation.