The study of the chemical composition of living organisms

 Matter = anything that has mass and takes up space  Elements = pure chemical substances that make up all matter and are composed of only 1 type of atom  Copper (Cu)  Atoms = smallest particles of an element that have the properties of that element  Made of protons, neutrons, & electrons

 Ionic bond = the chemical attraction between 2 ions by a transfer of electrons  Na and Cl transfer electrons to make NaCl  Ions = ions that gain or lose electrons that become electrically charged  Cation = positive ion (Na + )  Anion = negative ion (Cl - )

Is it more dangerous to swim in the ocean or in a lake during a lightning storm?  Substances that release ions in water  The electrically charged (either + or -) ions can conduct an electric current  For example, NaCl in H 2 O dissociates into Na + and Cl -  A salt is a compound composed of oppositely charged ions

 Na+ (sodium) is the major cation found outside of cells & is necessary for the transmission of nerve impulses and muscle movement  Hypernatremia – too much sodium in the bloodstream  Can simply drink more water!  Usually due to dehydration  Hyponatremia – too little sodium in the bloodstream

 Potassium (K+) is the major cation found inside cells & functions in transmission of nerve impulses and muscular function  Hyperkalemia - too much K+  Kidneys may not be working properly to secrete K+  Hypokalemia – too little K+  Kidney disease, poor diet, loss of electrolytes via excessive exercise/sweating

 movies/action_potential _cartoon.swf movies/action_potential _cartoon.swf  ation.com/sites/ /student_view0/ chapter14/animation__ the_nerve_impulse.html ation.com/sites/ /student_view0/ chapter14/animation__ the_nerve_impulse.html

 Acids are electrolytes that release hydrogen ions (H+)  HCl dissociates to H+ and Cl- in water  Bases are electrolytes that release hydroxide ions (OH-)  NaOH dissociates to Na+ and OH- in water

 Covalent bond = chemical bond formed by electron sharing between atoms  Molecule = a particle composed of two or more joined atoms  Hydrogen bond = a type of weak covalent bond between a hydrogen atom and an atom of oxygen or nitrogen

 Polarity of water  Hydrogen bonding in water  Heat capacity  Crystallization of solid water  Capillary action  Cohesion  Good solvent

 Organic = chemicals that include both carbon and hydrogen atoms (C and H)  Macromolecules: lipids, carbohydrates, proteins, nucleic acids  Inorganic = the chemicals that do not include both carbon and hydrogen  Water, carbon dioxide, salts, oxygen, etc.

 Control the cell’s use of energy by building up and breaking down molecules  Anabolic reaction– buildup of larger molecules from smaller ones  Requires energy  Catabolic reaction– the breakdown of larger molecules into smaller ones  Releases energy

 Provides all the biochemicals required for growth and repair  This is how proteins, carbohydrates, nucleic acids, and lipid chains are made  Dehydration synthesis- the anabolic process that joins small molecules by releasing a water molecule

 Occurs in digestion so the body can access energy from food  Hydrolysis- decomposes the biomolecules (carbohydrates, lipids, and proteins) and splits a water in the process

 Large molecules made up of smaller building blocks or subunits  Monomer = a single subunit that can bind with more of the same subunits to form a polymer  Polymer = a large molecule made up of many repeating subunits (monomers)  Make a model of a polymer, showing 3 monomers

 Work with your partner(s)!