Expert: Florence M Rollwagen - 3/26/2009

Question
How many moles of water are produced during dehydration synthesis of 3 moles of lysozyme a protein with 129 amino acids?

I am trying to avoid just asking you a homework question because I want to understand it. However my teacher left us with no equation or anything as to figuring this out. I've looked all up and down on the lab and all info he gave us and nothing is relevant to this. thanks for your help i appreciate it.

Answer
Hi Jimmy:  Thanks for your question.

The answer to your question is in the synthesis of lysozyme.  As you know, a dehydration synthesis removes water (HOH) from between two molecules and creates a covalent bond.   So this is a logic puzzle.

The real answer lies in the peptide bonds between the amino acid subunits.  So when we link 2 aa together, we remove 1 molecule of water.  When we add another aa, we take away another molecule of water.  So I think the answer will be for each molecule of the 129 aa sequence of lysozyme we will get 128 molecules of water.  Convert to moles and you're done.

Does that make sense?

Here is something about the synthesis of lysozyme:
http://www.pnas.org/content/104/12/4846.full

Good luck!

FM Rollwagen, PhD