# 1.5 Aromatic Interactions

> Aromatic Interactions (Module 1: The Building Blocks). Key concept: Pi stacking & cation-pi. Identify the three aromatic residues and their ring systems.

Aromatic Interactions (Module 1: The Building Blocks). Key concept: Pi stacking & cation-pi. Identify the three aromatic residues and their ring systems.

- Identify the three aromatic residues and their ring systems
- Explain what pi-electrons are and why aromatic rings attract each other
- Distinguish the two favourable stacking geometries, parallel-offset and T-shaped, from the unfavourable face-to-face one
- Build a stable aromatic arrangement by choosing the right orientation

## Links

- [Module 1: The Building Blocks](https://proteindesign.academy/module/1)
- [Introduction](https://proteindesign.academy/module/1/intro)
- [1.1 The Hydrophobic Effect](https://proteindesign.academy/module/1/1)
- [1.2 Electrostatics & Salt Bridges](https://proteindesign.academy/module/1/2)
- [1.3 Size & Shape: The Packing Game](https://proteindesign.academy/module/1/3)
- [1.4 The Special Characters](https://proteindesign.academy/module/1/4)
- [The Peptide Engineer](https://proteindesign.academy/module/1/capstone)