chapter 2- chemical basis of life

• Neutrons


  No electrical charge
• Protons


  Positive charges
• Electrons


  Negative charges
• Nucleus


  Formed by protons and neutrons
• Electron cloud


  Where electrons are most likely to be found
• Atomic number


  No of protons in each atom
• Mass number


  No. of protons + no. of neutrons
• Matter


  Anything that occupies space and has mass
• Mass


  Amount of matter in an object; kilogram
• Weight


  Gravitational force acting on an object
• Chemistry


  Concerned with atomic composition and structure of substances and the reactions they undergo
• Elements


  Simplest type of matter having unique properties
• Atoms


  Smallest particle of an element
• Chemical Bonding


  Electrons are transferred or shared between atoms
• Ionic Bond


  Electrons are transferred
• Covalent Bond

  Electrons are shared
• Polar covalent bond


  Unequal, asymmetrical sharing of electrons
• Polar molecules


  Molecules with asymmetrical electrical charge
• Nonpolar covalent bond


  Equal sharing of electrons bet. atoms
• Nonpolar molecules


  Molecules with symmetrical electrical charge
• Hydrogen Bonds


  Weak attraction bet the oppositely charged regions of polar molecules
• Molecule


  Two or more atoms that are chemically combined
• Compound


  Two or more diff. types of atoms that are chemically combined
• Dissociation


  Separation of ions in an ionic compound by polar water molecules
• Electrolytes

  Dissociated ions
• Chemical Reactions


  Substances interact either to form or to break chemical bonds
• Reactants


  Substances that enter into a chemical reaction
• Products


  Substances that result from the chemical reaction
• Classification of Chemical Reactions

  Synthesis - combination of reactants

  2. Decomposition - breakdown of larger reactants

  3. Exchange - decomposition + synthesis
• Anabolism


  Synthesis reactions that occur in the body
• Catabolism


  Decomposition reactions that occur in the body
• Metabolism

  Anabolic + catabolic reactions in the body
• Reversible Reaction


  Reactants can form products, products can form reactants
• Energy


  Capacity to do work
• Potential Energy


  Stored energy
• Kinetic Energy


  Energy caused by movement
• Chemical Energy


  Form of potential energy stored in chemical bonds
• Rate of Chemical Reactions

  Reactants

  2. Concentration

  3. Temperature

  4. Catalysts (increases the rate of chem reaction without itself being permanently changed or depleted)
• Acid


  Proton donor
• Base


  Proton acceptor