Introduction for the Interaction of Light with Biological Molecules

Overview

This lesson describes the nature of light, the energy within photons and how this energy may be transferred to biological molecules. In addition, the beneficial and harmful methods for de-exciting molecules will be described.

Objectives

At the completion of this lesson, students will be able to:

• Describe the nature of photons as quanta or packets of energy
• Predict the relative energy in a photon from its wavelength
• Describe the absorption process in terms of electronic state transitions
• Describe four different pathways for de-excitation:
  • Fluorescence or thermal decay
  • Transfer of energy
  • Triple state conversion
  • Photochemistry
• Differentiate between singlet and triplet electronic states
• Understand photosensitization in terms of free radical generation of reactive oxygen