Submited on: 09 Oct 2010 02:20:23 AM GMT
Published on: 09 Oct 2010 12:41:08 PM GMT
 
K. Michaelian responds to review by W. Fuss
Posted by Dr. Karo Michaelian on 21 Oct 2011 12:45:45 AM GMT

1 Is the subject of the article within the scope of the subject category? Yes
2 Are the interpretations / conclusions sound and justified by the data? Yes
3 Is this a new and original contribution? Yes
4 Does this paper exemplify an awareness of other research on the topic? Yes
5 Are structure and length satisfactory? Yes
6 Can you suggest brief additions or amendments or an introductory statement that will increase the value of this paper for an international audience? Yes
7 Can you suggest any reductions in the paper, or deletions of parts? No
8 Is the quality of the diction satisfactory? Yes
9 Are the illustrations and tables necessary and acceptable? Yes
10 Are the references adequate and are they all necessary? Yes
11 Are the keywords and abstract or summary informative? Yes
  • Other Comments:

    I thank Dr. Fuss for his review of my article. I would like to point out to Dr. Fuss that a 260 nm photon (where DNA and RNA absorb strongly) leaves 4.8 eV of energy. This energy is dissipated at the site of the nucleic acid base on which the single photon is absorbed and spreads out as diffusion of heat to the surrounding water. On reaching a volume of radius 4.9 nm, which could contain up to 20 base pairs, and given the specific heat of water of 4200 J/(K kg), the temperature of this volume of water would be raised on average by about 3°C. This would be sufficient to denature these small segments of RNA or DNA if the ocean surface temperature were just below its denaturing temperature at night and heated up by a couple of degrees in the day due to infrared absoption, as happens today on all ocean surfaces. This data, by the way, was included in the original article. Therefore, the proposed mechanism is plausible and we are now carrying out an experimental tests of it. I hope to have some data available in the near future. 

  • Invited by the author to review this article? :
    No
  • Have you previously published on this or a similar topic?:
    Yes
  • References:
    Michaelian, Karo,. "Thermodynamic Origin of Life" (abs). ArXiv.org., 2009. Michaelian, Karo, “Thermodynamic Dissipation Theory for the Origin of Life.” Earth Syst. Dynam. 2: 37–51, 2011a. Michaelian, Karo, “Biological Catalysis of the Hydrological Cycle: Life’s Thermodynamic Function”. Hydrol. Earth Syst. Sci. Discuss. 8: 1093–1123, 2011b. Michaelian, K. and Manuel, O., Origin and Evolution of Life Constraints on the Solar Model, Journal of Modern Physics, Vol. 2, No. 6A, PP.587-594, 2011c DOI: 10.4236/jmp.2011.226068 Michaelian, K., Entropy Production and the Origin of Life, Journal of Modern Physics, Vol 2, No. 6A, PP.595-601, 2011d DOI: 10.4236/jmp.2011.226069
  • Experience and credentials in the specific area of science:

    Area of expertise: Non-equilibrium thermodynamics.

  • How to cite:  Michaelian K .K. Michaelian responds to review by W. Fuss[Review of the article 'Homochirality Through Photon-induced Melting Of Rna/dna: Thermodynamic Dissipation Theory Of The Origin Of Life ' by Michaelian K].WebmedCentral 2011;2(10):WMCRW001029
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Untitled
Posted by Dr. Fuss Werner on 07 Feb 2011 07:23:50 AM GMT

  • Other Comments:

    The author K. Michaelian presents an interesting idea on the origin of biological homochirality: Generation of circularly polarized UV light from linearly polarized light scattered and then totally reflected below the surface of a warm ocean. If the temperature was near the melting point of RNA, this light could have melted preferably one enantiomer of it (the one with the right circular dichroism), so that it could more easily reproduce itself during subsequent cooling. However I have doubts, in particular point 2:
    (1)   Although a reference is quoted, the author should briefly explain, why or under which conditions the handedness of the circular polarization is independent of the direction of scattering, so that in can be right-handed in the late afternoon.
    (2) The electronically excited RNA to a nonnegligible part (around 1%) undergoes irreversible photochemistry (e.g. cyclodimerization of bases), but to the largest part undergoes internal conversion within around 1 ps. The internal energy is then dissipated to the solvent in about 10 ps (in nonpolar solvents, see e.g. [1]) or shorter (in water). Any ground-state reaction takes longer than energy transfer, and a cooperative phenomenon such as melting would certainly take >1000 times more. If the RNA melts due to the temperature rise of the water, both enantiomers are affected. This would not be the case, if the average distance between RNA molecules is (due to low concentration) longer than the range of heat conduction within the melting time (e.g. a few ns); however, at such low concentration the temperature rise would be negligible, or it would be dominated by other absorbers.
    (3) If the authors want to consider such low concentrations, they should also pay attention to the suggestion [2] that a single self-reproducing molecule at the origin would correspond to 100% enantiomer excess and would automatically lead to homochirality without any external physical interaction. The two types of suggestions (with and without physical driving force) have recently been analysed by statistical means [3] (which could also be done with the author's proposal).
    (4) The text is in ASCII (no Greek letters, no powers of 10 ...) which makes is hard to read in some parts.
    [1] U. Hold et al., Ber. Bunsenges. Phys. Chem. 101 (1997) 552-565 and literature quoted therein.
    H. Hippler et al., J. Chem. Phys. 79 (1983) 239-246 and literature quoted therein.
    K.W. Egger, J. Am. Chem. Soc. 90 (1968) 6-11 and references quoted there.
    [2] H. Kuhn, Angew. Chem. Int. Ed. 11 (1972) 798 and later works.
    [3] G. Lente, J. Phys. Chem. A 110 (2006) 12711.
    W. Fuß, Chirality 21 (2009) 299.

  • Invited by the author to review this article? :
    Yes
  • Have you previously published on this or a similar topic?:
    Yes
  • References:
    None
  • Experience and credentials in the specific area of science:
    None
  • How to cite:  Werner F .Untitled[Review of the article 'Homochirality Through Photon-induced Melting Of Rna/dna: Thermodynamic Dissipation Theory Of The Origin Of Life ' by Michaelian K].WebmedCentral 2011;2(2):WMCRW00441
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I thank Dr. Fuss Werner for his review of my article and for his comments on improving the manuscript. I would like to point out to Dr. Werner that a 260 nm photon (where DNA and RNA absorb strongly) leaves 4.8 eV of energy. This energy is dissipated at the site of the nucleic acid base on which the single photon is absorbed and spreads out as diffusion of heat to the surrounding water. On reaching a volume of radius 4.9 nm, which could contain up to 16 base pairs in linear segment (or up to 50 bp if folded), and given the specific heat of water of 4200 J/(K kg), the temperature of this volume of water would be raised on average by about 3°C. This would be sufficient to denature these small segments of RNA or DNA if the ocean surface temperature were just below its denaturing temperature at night and heated up by a couple of degrees during the late afternoon due to infrared absoption, as happens today on all ocean surfaces. This data was included implicitly in the original article, but it is made explicit here. Therefore, the proposed mechanism is plausible and we are now carrying out an experimental tests of it. I hope to have some data available in the near future.
Responded by Dr. Karo Michaelian on 21 Oct 2011 01:00:58 AM