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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: The bleeding nun on December 17, 2005, 12:30:48 AM

Title: hydrogen bonds in proteins
Post by: The bleeding nun on December 17, 2005, 12:30:48 AM
Hi this is my first post here,

 

I have the following problem: I want to know how many hydogen bonds (50 kJ each) are needed to fold up a protein at 300K knowing that the protein will be compressed to 10 times its original size after it has been folded.

 

I have the following  entropy equation:

?S= -3/4[R2/r2 + r2/R2]

where R and r are the two radius before and after the fording. So that R=10r

when I solve for the equation i get ?S= 150

and then I have the following equation:

?S= ?H - T?S

 

Where T is the temperature at which the protein folds.

 

Puting in my values, I get H=45000 and now I have to divide it by the 50kJ to get the number of H-bonds. This gives me 2250 bonds

 

I would like to know what are the units I am working with for S and H. I mean, when I first calculated my ?S, is the reslut in J or kJ? And I also wanted to know how you would solve the same problem

 

Thanks a lot!!!