BIOL 1000 Study Guide - Midterm Guide: Membrane Transport Protein, Electron Transport Chain, Optical Microscope
9 Oct 2013
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Document Summary
Light (electromagnetic radiation) is the visible region of the electromagnetic spectrum, humans can detect with their eyes. Light is described according to its wavelength but it behaves as particles called photons (small units of light energy). Shorter wavelengths than light contain enough energy to destroy the bonds that are in living things. Longer wavelengths are energetically relatively weak and would not supply enough energy to move an electron from ground state to an excited state, also absorbed by water. Pigments: major class of molecules hat are efficient at absorbing photons. (chlorophyll a, retinal (in vision), and indigo (dye jeans)) They all share a common feature critical to light absorption: conjugated system: a region where carbon atoms are covalently bonded to each other with alternating single and double bonds= delocalization of electrons. None of these electrons are closely associated with a particular atom or involved in bonding and thus are available to interact with a photon of light.
