Goals and Objectives:
This is a good review chapter that goes over some of the basics of light energy and the plant pigments that can respond to light energy.  Although I will not have exam questions that directly from this chapter, the information will be useful to your understanding of photobiology.

1.     Physical Nature of Light
• Be able to draw a line that represents the electromagnetic spectrum and label the wavelengths of light that are arrayed long this line.
• Be able to explain how the wavelength energy changes along the electromagnetic spectrum.
2.     Absorption and fate of light energy
• Be able to describe what happens to a plant pigment when it absorbs light energy.
• What possible four methods of energy dissipation can occur in plant pigments?
3.     Absorption and action spectra
• What is an absorption spectrum?
• Draw an absorption spectrum for chlorophyll.
• What is an action spectrum?
• What is the relationship between absorption and action spectra of plants doing photosynthesis?
4.     Measuring light
• List the three parameters of primary concern when describing light.
5.     The natural radiation environment
• Infrared Radiation
• What is the greenhouse effect?
• What is involved in the  creation of the greenhouse effect and how has it affected the earth?
• Ultraviolet Radiation
• How does ultraviolet light affect organisms?
• How is ultraviolet light's impact on the plant controlled, and what changes are occurring in this control mechanism?
• Visible Radiation
• What are the two most significant changes in visible light over a 24 hour period?
• Describe how these two factors change over a 24 hour period.
6. Photoreceptors
• For each of the following photoreceptors, describe the importance of the pigment to photobiology and the important light wavelengths that are absorbed.
• Chlorophylls
• Phycobilins
• Carotenoids
• Cryptochrome
• UV-B receptors
• Flavonoids
• Betacyanins