In the cell, there are no energy fields and interactions that could provide for transmutation of atoms. The isotope effect is to change the ratio between isotopes of elements such as carbon and hydrogen, and this effect is clearly recorded in biochemical reactions. Well known changes in the carbon isotopes ratio in C-4 and C-3 plants. Apparently the presence of isotopes with non-zero nuclear spin can play an important role in isotope effect besides the difference in mass numbers of isotopes. In particular, it relates to isotopes of magnesium  which has isotope 25Mg with non-zero nuclear spin.

Dmitry Grodzinsky, with all due respect, what exactly do you mean by "In the cell, there are no energy fields and interactions that could provide for transmutation of atoms." ? Please explain, extrapolate.

An isotope is an entity that "popular speaking" it has an "internal clock", that after some given time, for instance the isotope 14C (carbon-14), after 5715 (5730) years will be half in quantity. Sure, the atoms are "circulating", changing with fresh ones (from air, CO2 etc) in the case of a living cell, but we have no guaranty the all "old atoms" leave the cells and all C atoms are new, so that apparently the quantity remains almost the same, but nothing guaranties us that a given isotope ( example 14C ) can not transmute while being located in a cell (alive) . It simply it came its time to transmute, due to its internal clock (I call it). No much is being known about the mechanism and the 1/2 time. It is all based on some statistics, assumptions, and mathematical calculations that often prove to be incorrect.

Nothing will stop a given isotope, in a living cell or in a body without any life, to transmute into an other atom ! Transmutation probably can be accelerated or slow down, but they take place even at 0 Kelvin. Does it? It takes place in the interstellar space, far from any heat.

Energy , of all different kinds, is present everywhere. I would say, and sure you agree with me, that energy is the ONLY thing that is found absolutely everywhere.

I personally see all existence as energy, mater being a form of energy's existence and we refer to mater for the purpose of communication only even in the case of intangible mater (but that's an other area, still not too far from our subject) .

Back to transmutation of isotopes: The energy is internal, within the atom (an isotope, that is like a bomb with internal clock) that at a certain time, for instance using the example of 14C, it will become 14N (nitrogen 14).

Nothing can stop an isotope to transmute, but external energies can possibly help it to transmute faster or slower, we do not know much about it.

On the other hand, since we are talking about external forces, an atom under the incidence of a cosmic ray (CR as external force), does not have any "protection" being connected with other atoms, being part of a small or large molecule. Again, as example, If a 14N atom is hit by a CR , strong enough, even so being at the Earth surface level or up at high altitude, it will become carbon-14.

Sure, the living cell it has the ability to adapt, self-repair, etc... still, this is what we are talking about here: What if the atom (Isotope)  transmutes while it has an active roll in the living cell ?

In the question I was not referring only to difference in mass or numbers of isotopes but rather the effect it has upon the cell's stability, function, future development, the transmutation of any given atom by either the "internal clock, internal forces" of the isotope (more likely) or, why not, the external forces due to CR of variety of energies , high, low, bombardment found and sea level, under ground, and surely much more at higher altitudes.

Thank you for your answer / participation , much more so you are so far the only person to answer the question being addressed exactly 5 years ago ( Dec 8, 2010).

Lets keep in personal contact please. The subject appears to be easy but in many ways it is tricky , I think.

Regards,

Adrian TW