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Example Questions
Example Question #1 : Compound Quantification
The visible spectrum is typically between 390-700nm. Shorter wavelengths are responsible for the purple end of the color spectrum, while red is perceived in the eye from the longer wavelengths. -carotene is able to absorb light at a maximum value of 497nm.
-carotene is found in carrots. What would need to happen to -carotene in order for the color of carrots to become more yellow?
The number of amount of conjugated double bonds must be reduced
The number of amount of double bonds must be increased
The -carotene must become less saturated
The amount of -carotene in carrots must be reduced
The number of amount of conjugated double bonds must be reduced
The wavelength of light absorbed by a pigment is related to the number of conjugated double bonds in the molecule. The eye will begin to perceive color when the number of conjugated double bonds in a molecule becomes around eight. At this point, the color yellow can be perceived by the eye. In order for -carotene to give carrots a more yellowish color, it must have a change in the number of conjugated double bonds so that the pigment absorbs a shorter wavelength of light. This way, it will emit complementary light with a wavelength closer to yellow on the visible spectrum.
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