BIO 1030 Lecture Notes - Lecture 5: Cell Nucleus, Organic Chemistry, Electronegativity
22 Jan 2017
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Document Summary
Chemical formulas and reactions: reactants- molecules that participate in reactions, products- molecules formed by reactions, equation is balanced if the same number of each type of atom occurs on both sides of the arrow. Wate(cid:396)"s importance to life: life began in water, single most important molecule on earth, all organisms have 70-90% water. The structure of water: polar covalent bond. Oxygen is more electronegative than hydrogen: hydrogen bond. Slightly positive hydrogen of one water molecule attracted to the slightly. Properties of water (know what each of these are) negative oxygen in another water molecule: solvency, cohesion and adhesion, high surface tension, high heat capacity, high heat of vaporization, varying density. Water is a solvent: due to the polarity and hydrogen bonding, water dissolves many substances, hydrophilic. Cohesion: ability of water molecules to cling to each other due to hydrogen bonding. Adhesion: ability of water molecules to cling to other polar surfaces.
