C4: Solar Energy
Pigments in plants are colored due to conjugated double bond systems. If a certain pigment absorbs red and green and/or yellow light as a result of its conjugation, then blue or purple light will be reflected. Chlorophyll absorbs red and blue light, but reflects green.
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In this process to form biodiesel, the vegetable oil is typically heated with a sodium or potassium hydroxide catalyst along with methanol to produce the methyl ester, or ethanol to produce the ethyl ester of the triglyceride.
Page 677 provides a list of the advantages and disadvantages of biodiesel. My understanding is that you need to know these for the exam.