Biology 1202B Lecture Notes - Lecture 3: Electromagnetic Spectrum, Cellular Respiration, Radiant Energy
25 May 2016
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Document Summary
Electromagnetic energy is given off by the sun due to the fusion of hydrogen. The distance between the crests of the waves determines type. The portion of the electromagnetic spectrum that humans can see. Act like particles in motion - they have a fixed quantity of energy. The wavelength of light is inverse to the amount of energy. Violet light has more energy than red light. Light has no mass but still interacts with matter. For light to be used as a source of energy, it must be absorbed. Molecules which are very efficient at absorbing photons. Due to bonding arrangement of carbon atoms. Alternating single and double bonds, conjugated system, electrons are delocalized and available to interact with a photon of light. Pigments differ in the wavelengths that they absorb. Some absorb more than one wavelength (have multiple excited states) A pigments colour depends on what wavelength it absorbs. Colour is the light that the pigment does not absorb.
