Stevie D Posted December 16, 2009 Share Posted December 16, 2009 This is my first post here, so hello everyone. Making my foray into the wonderful world of science via an Access course (read A-level for mature students) in Marine and Environmental Science. See you at the lab in a few years' time. Anyway, onto the question. Working away on a biochemistry module at the moment (RH5/3/WW/003). Trying to rationalise to myself the formation of sucrose from glucose and fructose, as you may have determined from the thread title. I found this website: http://dl.clackamas.edu/ch106-07/sucrose.htm What I don't understand is their explantion of how b-D-fructose in standard orientation, shown here: ...gets flipped to b-D-fructose in inverted orientation: Are these two separate isomers? I've tried mentally rotating the first molecule in all three dimensions but still can't find a way to do it so that it ends up looking like the second one. I'd appreciate an explanation by more learned people. Cheers, Steve Link to comment Share on other sites More sharing options...
science101 Posted December 16, 2009 Share Posted December 16, 2009 I can ashore you steve that it is not possible. Sorry about your problem, no help here. Link to comment Share on other sites More sharing options...
zule Posted December 20, 2009 Share Posted December 20, 2009 In order to go from an isomer to the other, the ring has to open ant then to close again in the new conformation. This is called mutarotation. Link to comment Share on other sites More sharing options...
Abdulkareem Posted December 20, 2009 Share Posted December 20, 2009 the problem u have there is the ring is not easy simplify and u u can find other ring i can explain it for in a simple manner. u know sucrose hydrolysis by formation of glucose and fructose. Link to comment Share on other sites More sharing options...
Stevie D Posted December 21, 2009 Author Share Posted December 21, 2009 In order to go from an isomer to the other, the ring has to open ant then to close again in the new conformation. This is called mutarotation. I see, thanks. Link to comment Share on other sites More sharing options...
MBGuru Posted February 28, 2010 Share Posted February 28, 2010 Draw a line that goes through the furan ring Oxygen atom and splits in half the bond that connects Carbon atoms 3 and 4, that would be the ones closest to you and each one of them is conected to a -OH group. C4-----C3 Now spin the top molecule by 180 degrees and you will get the one on the bottom. But this time C4 will be to your right and C3 to your left. Link to comment Share on other sites More sharing options...
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