structural

## What I do - Explain molecular structure principles - Describe protein structure organization - Discuss structural analysis methods - Analyze molecular interactions - Connect structure to function - Explain structural determination techniques ## When to use me - When learning structural biology basics - When explaining protein structure - When studying molecular interactions - When preparing educational content ## Key Concepts ### Biomolecular Structure **Proteins** - Amino acids linked by peptide bonds - 20 standard amino acids - Primary through quaternary structure - Folding into 3D conformation **Nucleic Acids** - DNA: Double helix (B-form) - RNA: Various structures (A, Z, hairpins) - Nucleotides: Phosphate-sugar-base ### Molecular Interactions ```python # Common interactions interactions = { 'covalent': 'Strong, ~350 kJ/mol, shared electrons', 'ionic': 'Moderate, ~250 kJ/mol, charge-charge', 'hydrogen': 'Weak-moderate, ~20-40 kJ/mol, X-H---Y', 'hydrophobic': 'Weak, ~5 kJ/mol, entropy-driven', 'van_der_waals': 'Very weak, ~1 kJ/mol, induced dipoles' } # Bond types in biomolecules bonds = { 'peptide': 'N-C, backbone', 'glycosidic': 'Sugar-sugar, sugar-base', 'phosphodiester': 'Nucleotide backbone' } ``` ### Techniques Overview - X-ray crystallography - NMR spectroscopy - Cryo-EM - Mass spectrometry - Spectroscopy (UV, CD, fluorescence) - Computational modeling ### Structure Databases - PDB: Protein Data Bank - NCBI Structure - EMDB: Electron Microscopy DB - AlphaFold DB