BI110 Chapter Notes - Chapter 1: Soot, Chlorophyll, Algae
Document Summary
1. 1 - the physical nature of light. Light serves 2 important functions on earth. Provides organisms w/ info about surrounding, physical world. Green alga (chlamydomonas reinhardtii) uses light for energy and info. Contains one chloroplast to harvest light energy. Contains eyespot (light sensor); allows cell to gather info about location and intensity of light source. Light is present on earth due to distance. By converting hydrogen into helium, sun converts tonnes of matter into energy. Energy emitted as electromagnetic radiation; travels as wave. Light = visible light spectrum (b/w 400 nm and 700 nm) Photons --> stream of energy particles; light composed of photons. Particle-wave duality --> light has properties of waves and streams. Longer wavelength = less energy; shorter wavelength = more energy. When photon energy does not equal energy difference b/w ground state and excited state. Light absorption causes electron to enter excited state (higher energy level/orbital)
