Biology Talk Biology Talk    FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Thermodynamic change, amino acids to a protein.          Biology Talk Forum Index -> Biology Talk -> Microbiology View previous topic :: View next topic   Author Message Jint Lynn Guest Posted: Sun Mar 16, 2008 2:59 am    Post subject: Thermodynamic change, amino acids to a protein. Here is the original question. It talks about thermodynamic change. Sorry for my poor English. _____________________________________________________________________ When a protein forms from amino acids, the following changes apply: A)+ÄH, -ÄS, +ÄG B)+ÄH, -ÄS, -ÄG C)+ÄH, +ÄS, +ÄG D)-ÄH, -ÄS, +ÄG E)-ÄH, +ÄS, +ÄG ANS:A (PS. Ä=delta, I don't why the symbol could not be showed correctly in my last post) ______________________________________________________________________ Why? Who can explain it? Thank for your reply. Back to top   Ads Advertising Sponsor Bob Guest Posted: Sun Mar 16, 2008 9:07 pm    Post subject: Re: Thermodynamic change, amino acids to a protein. On Sat, 15 Mar 2008 19:59:43 -0700 (PDT), Jint Lynn <gplynn.leu@gmail.com> wrote: Quote: Here is the original question. It talks about thermodynamic change. Sorry for my poor English. _____________________________________________________________________ When a protein forms from amino acids, the following changes apply: A)+?H, -?S, +?G B)+?H, -?S, -?G C)+?H, +?S, +?G D)-?H, -?S, +?G E)-?H, +?S, +?G ANS:A (PS. ?=delta, I don't why the symbol could not be showed correctly in my last post) Ah, got it. The problem is not English, but computer. Usenet (these groups) use basic ASCII, and Greek letters (and many other "special characters") do not come through (at least for many users). One solution is to use d for delta -- and then say so, just as you did above. Ok, now to the question... Think about how protein is made and broken down. Which process is "spontaneous", (favorable) and which requires energy? This tells you the sign of dG. The sign of S is also "intuitive" -- at least if one does not try to make it too hard. (dS can be complex, but is not in this case.) A simple view of S relates to ordering. Which is more "ordered" and which is more "constrained"? That gives you the sign of dS. I'm not sure of an easy way to "guess" the sign of dH. Some combinations of signs for dG and dS will dictate what the sign of dH must be, but that won't help here. Perhaps someone else will come up with something. Are you sure someone (book?) didn't drop a hint on this? In any case, the sign for dH turns out to be the same as the sign for dG. But I cannot offer a reason offhand, other than it is measured. bob Back to top   Ads Advertising Sponsor Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Biology Talk Forum Index -> Biology Talk -> Microbiology All times are GMT Page 1 of 1   Jump to: Select a forum Biology Talk----------------Biology Talk-- MicrobiologyEvolutionPsychobiologyBiotechnology  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum 109 Attacks blocked Powered by phpBB © 2001, 2005 phpBB Group