BIOL 103 Chapter Notes - Chapter 2: Hydrolysis, Protein Structure, Cell Nucleus
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Atom: smallest unit of matter: contains the nucleus: nucleus is made of equal numbers of protons (positively charged particles) and neutrons (neutral charged particles) i. The nucleus is like a powerful center of the atom: electrons (negatively charged particles) orbit around the nucleus on shells i. Fewer or more neutrons than the usual number for that element. Atoms combine (or bond) to form molecules (which are two or more atoms in a bond) *remember that electrons orbit around the shells and there could be only a certain amount of electrons to fit the shells. Some of these electrons can be like leftovers and they interact with other electrons from the other leftovers electrons from another atom. Types of bonds: covalent: sharing of all electrons between the atoms i. ii. H-h, h20, and o-o: ionic: an attraction between ions of opposite charge i. ii. iii. An electrically charged atom or molecule (either positive or negative) is called an ion.