| Bond that joins amino acids.
H H H H H H O H H
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HN-C-COOH + HN-C-COOH => HN-C-C -N-C-COOH + H2O
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X Y X Y
A little funky looking, but the peptide bond is where it says:
O H
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C -N
The OH on the carbon and the second H on the nitrogen bond to form water, and the nitrogen bonds with the carbon to join the amino acids, creating a protein. Yay. | 
