BIO120H1 Study Guide - Midterm Guide: Megafaunal Wolf, Character Displacement, Holocene Extinction
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BIO120H1 Full Course Notes
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Document Summary
Need for life: source of energy, carbon, liquid water. 4 billion years ago interstellar dust cloud collapsed into swirling accretion disk which gave rise to sun & planets. Fragile complex organic molecules survived heat of solar system formation by sticking together in comets on edge of disk (temp. Comets & other cloud remnants carried molecules to earth. Interstellar ice forms when molecules like methanol, water, hydrocarbon freeze onto granules of silicate in interstellar clouds. Ultraviolet radiation from nearby stars breaks some chemical bonds in frozen compounds. Broken down molecules recombine into complex compounds (e. g. quinines, nitriles, ethers, alcohols) which would not form if fragments could float away. Six-carbon molecule (htm) also created known to create amino acids in warm, acidic water. Molecules from space that naturally form capsule-like droplets in water could have provided enclosure (similar to plasma membrane) for prebiotic molecules.
