Glycylglycine Planar Peptide Bond-MCAT Study

Building amino acid models is one an effective way to visualize peptide bond formation and understand a fundamental characteristic of protein structure. Our model of glycylglycine, a dipeptide made of two glycine units, is a good introduction to how amino acids link via condensation reactions to form peptides and proteins.

Aspartame, for example, is a well-known artificial sweetener that highlights real-world relevance: it is a dipeptide composed of the amino acids phenylalanine (Phe) and aspartic acid (Asp), with the molecular formula C_??H_??N_?O_?. By modelling such dipeptides, students can clearly observe how peptide bonds form and how the geometry of the nitrogen atom changes—from tetrahedral in free amines to planar when involved in a peptide bond.

These changes are not just structural—they’re key to understanding enzyme activity, protein folding, and the chemical properties that drive biological function. Whether you're studying for a biochemistry midterm or reviewing amino acid structures for the MCAT exams, building these molecular models reinforces learning through tactile and visual feedback.

Note: This model set comes with 2 tetrahedral & 1 planar nitrogen. When combining two amino acids via a peptide bond, the planar version is substituted for one of the tetrahedra as shown in the image.