Biology 1202B Lecture Notes - Lecture 2: Nitrogenous Base, Photomorphogenesis, Thermodynamics
29 Jan 2018
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Document Summary
Light is a source of energy and life is a source of information. Direct or indirect source of of energy that sustains virtually all organisms. Provides organisms with information about the physical world that surrounds them. Ex: green alga, single celled photosynthetic eukaryote that contains a chloroplast which harvests light energy. Each has a light sensor called eyespot that helps the organism understand the intensity of light source. The sun gives off electromagnetic radiation which travels in the form of a wave at a speed of 1 079 252 848 km/h - speed of light. Light is the most commonly defined as the portion of the electromagnetic spectrum that the human eyes can detect. It is a very narrow portion spanning from 400 to 700 nm. Light is composed of a stream of energy particles called photons. The light has properties of both a wave and a stream of photons which is known as particle- wave duality.
