3. Please explain how Scatchard analysis is performed to study receptor-ligand interaction.

(二)請回答下列問題1. The tertiary structure of protein may be studied by four techniques, x-ray crystallography, NMR, electron microscopy and mass spectroscopy. Please describe the principles behind these techniques. Please discuss their advantages and drawbacks. Similarities exist between NMR and mass spectroscopy when they are used for structure analysis, please explain why?