BIOL 1000 Lecture Notes - Lecture 2: Electromagnetic Spectrum, Melanin, Cellular Respiration
Document Summary
Light is visible region of electromagnetic spectrum that humans can detect w/eyes. Light being a stream of energy particles. Absorption of photon by a molecule results in energy being transferred to an electron which causes energy to move to a higher-energy excited state. Absorption of light occurs when energy of photon is transferred to an electron w/in a molecule. Excites the electron, moving it from the ground state to a higher energy level. Photon can be absorbed only if energy of the photon matches the amt of energy needed to move electron from the ground state to specific excited stage. If it doesn"t match, photon of light is not absorbed; it is transmitted through the molecule or reflected. Photon absorption is intimately related to concept of color. Pigment: molecule that can absorb photons of light. Conjugated system: carbon atoms are covalently bonded to each other w/alternating single and double bonds, results in delocalized electrons.
