BIOL 1000 Lecture Notes - Lecture 1: Delocalized Electron, Photon Energy, Electromagnetic Spectrum
Document Summary
Light: a source of energy, sunlight = electromagnetic radiation, pla(cid:374)ck"s e(cid:395)uatio(cid:374): e=ch/(cid:449)a(cid:448)ele(cid:374)gth. Definition of light (visible light): portion of the electromagnetic spectrum that humans can detect with their eyes (400-700 nm) Features of light: abundance and ability to interact with life. Light encounters matter: absorbed by pigment molecules, reflected, transmitted. Absorption of energy from a photon: for light to be used as energy, light must be absorbed, photon energy has to match the energy needed to move the electron from the ground state to the excited state. Pigment molecules that can absorb photon of light. (colours) Electrons capture photons/energy that can be used to do work. Melanin produced by melanocytes absorbs short wavelength light and uv radiation. Eye colour is determined by amount of melanin in your iris. Brown eye light absorbed by melanin in iris. Long wavelengths of light are more easily absorbed. Light is converted into potential energy stored in chemical bond of food molecules.
