Biology on Cell 60,000,000,000,000 for $1 Structure of matter Element: a substance that can’t be broken down into simpler chemical substances Atom: the smallest particle of an element that has the characteristics of that element. Page 147 Nucleus The center of the atom , made up of p+ and n Protons • Positively charged particles (p+) Neutrons Particles that have no charge (n) Electrons Form a cloud around the nucleus, negatively charged particles (e-) Chemistry of Life Major chemical elements in cells Carbon Hydrogen Nitrogen Oxygen phosphorus Sulfur Trace elements Trace elements Elements that are present in living things in very small amounts. Properties of water Cohesion: The intermolecular attraction that holds molecules and masses together Adhesion: The physical attraction or joining of two substances, especially the macroscopically observable attraction of dissimilar substances. Properties of water cont. Heat capacity: water is like an insulator that helps maintain a steady environment when conditions fluctuate. Solvent properties: water is polar, which allows water to dissolve many compounds like salt. Water properties cont. Water expands when it freezes Helps form soilwater gets in cracks freezes and breaks the rocks. Ice is less dense than water. How would these properties help contribute to the maintenance of cells and living organisms? Enzymes Find the definition in your book. What role would enzymes take in cell chemistry?