BIOL 1410 Lecture 2: 2 - TOPIC II - CHEMICAL LEVEL OF ORGANIZATION
15 Dec 2015
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Topic ii: knowledge of basic chemistry needed for understanding. Difference between healthy and diseased person: structure of an atom. Note: atoms are electrically neutral the number of e- and p+ is equal (neutrons may not be equal to these: ions. If an atom loses or gains an electron, it is no longer neutral and becomes an ion. Atom gains e-(s): becomes a ve ion (anion) Atom loses e-(s): becomes a +ve ion (cation) Bond (hold) atoms together to form molecules. Types of bonds: ionic bond (ions formed) - atom to atom transfer of e- The positive (na+) and negative (cl-) ions attract. In h2o nacl dissociates (dissolves/separates/ionizes) forming the bond into ions: na+, cl- 1: covalent bond - sharing e- between atoms. These chemical bonds allow the formation of chemical compounds which may be organic or inorganic: organic substances - covalently bonded carbon (c) atoms. E. g. carbohydrates, proteins, lipids and nucleic acids: inorganic substances usually lack c atoms.
