From pierre-m.verville at hotmail.com Fri Aug 4 09:58:00 2006 From: pierre-m.verville at hotmail.com (pierre verville) Date: Fri Aug 4 14:54:55 2006 Subject: [Biothermokinetics] Photosynthesis: exothermic or endothermic? Message-ID: A new molecule have to be exoergic (exergonic ?). Because ortherwise it is unstable ( a very short life). In order to say endoergic you have to consider two molecules of water to provide the four protons for the basic monomer. Is the oxygen of photosynthesis endo or exo ... thermic. I propose exothermic. For me exergonic is a term to be utilized in when it is related to biology instead of chemistry. For photosynthesis I am not sure which to utilize. If the oxygen is exo then when it is forming the former molecule was in a liquid state to become what, with an exo potential of a reaction. ((an exergonic reaction have more than heat, e.g. the position in the outer shells as for P)) I would have had a lot more to tell about that question. I even found something in the famous top review of chemistry of the u.s.a. . When I try to begin a discussion with the staff of my university they panicked. Up to now those who try to answer that say : endothermic, endergonic. And they have a curious redox serie of reaction. A true redox reactions come at once, not successively. There is not a wandering electron that make the oxidized or reduced state, climbing the photosystems energy or so on. I found the father of the expression also. So as a student I have done a lot of research for that question. And I desire to be evaluate officially. But I want to know what it entails and so on. Think about it. The earth is wandering in a very cold cosmos. If photosynthesis is endo...... then photosynthesis is of no help in this fight against the cosmos : the heat fight. Waiting for an answer, sincerely yours pierre-m.verville@hotmail.com _________________________________________________________________ Jouez ? Q6 et vous pourriez GAGNER de fabuleux prix. http://q6trivia.imagine-live.com/frca/landing From atzus at gmx.de Tue Aug 8 03:16:08 2006 From: atzus at gmx.de (atzus@gmx.de) Date: Tue Aug 8 07:35:19 2006 Subject: [Biothermokinetics] Constructing a large model with few parameters Message-ID: <44D84848.2000401@gmx.de> Hi all. First of all: The btk-mca newsgroups - the one on yahoogroups.com and the one on bio.net - have been very inspiring. It is very unfortunate that open discussions like these are hard to find. If anyone can hint me to more material on the web with this quality, please write. On topic: I would like to build a bacterial model with ca. 200 reactions and as few parameters as possible. I'm not interested in exact reproduction of flux and concentration data, but the trends (rises & falls) would be sufficient. Therefore, my first idea is to build a model with mass action kinetics (which makes use of equilibrium constants and has only one parameter left) and add only a few more detailed rate laws at critical points. Questions: 1. Does this make sense? What would be a better approach? 2. How do I identify these critical points (e.g. large equilibrium constant, enzymes which are regulated by feedback inhibition, ...)? Looking forward to your suggestions, Kai PS: Cross-posting is intended, please don't get offended. From nnairn at allozyne.com Wed Aug 9 11:42:54 2006 From: nnairn at allozyne.com (Natalie Nairn) Date: Wed Aug 9 14:33:31 2006 Subject: [Biothermokinetics] Reducing agents for protein chemistry Message-ID: <0D9D26A1D32C6A4BA601BED8E13D516E81FAE5@exchange.acceleratorcorp.com> Hello, I happened to run across your post on the Btk-mca mailing list looking for a listing of redox potentials for common reducing agents, way back in 1999. Did you ever happen to get a list, if so could you send me a link? Thanks, Natalie ------------------------------------------------- Natalie Winblade Nairn, Ph.D. Senior Scientist Allozyne 1616 Eastlake Ave E Seattle WA 98102 206-957-7324 nnairn@allozyne.com ------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.bio.net/bionet/mm/btk-mca/attachments/20060809/e6a17bcd/attachment.html