Peptide V2.0

This is an upgraded version of my other Thing - Peptide Backbone.

Printing these pieces allows the user to quickly assemble simple peptide backbones with aliphatic side chains (e.g. glycine, alanine, valine, leucine, isoleucine, leucine). The fixed and rigid atoms are fused together into single pieces, while rotatable bonds are represented by pegs and 1/8" ID tubing, allowing the user to rotate the bonds to form secondary structures (alpha helices and beta strands).