NOTES: Unit 1-Basic Chem Review NAME HOUR

(1) What is Biochemistry? The chemistry of living things Study of… –biological elements or chemicals –biomolecules –organic molecules

(2) Atoms Atom = Basic Unit of Matter Structure: –Nucleus = Protons (+) and Neutrons (0) –Electrons (-)  Orbit around –Valence Electrons = Outermost Electrons EVERYTHING is made of atoms. Atoms Bonded  Molecule

(3) Valence Electrons Outermost Electrons –Electrons orbit in “shells” around atom –Last Shell “wants” 8 Valence Electrons Cause Bonding & Reactivity –If atom does NOT have 8 Valence Electrons… –Unhappy, Unstable atom –Atoms “gets” happy by bonding and reacting with other atoms

(4) Bonds Bond = Valence Electron interaction between atoms. Types of Bonds: –Covalent –Ionic –Hydrogen Forming Bonds = Work  Stored Energy Breaking Bonds = Easy  Release Energy

(5) Ionic Bonds One atom “loses” its valence electron/s One atom “steals” other valence electron/s Metal + NonMetal NOT common in organic compounds.

(6) Covalent Bonds Sharing of Valence Electron/s NonMetals COMMON in organic molecules Strong

(7) Hydrogen Bonds Weak Exists between H(+) and a more (-) atom Common in: –Water –DNA –Enzymes

(8) Polarity Polarity = Difference in Charges Certain atoms have a “greater” pull on valence electrons…. –BIGGER pull = MORE negative –SMALLER pull = MORE positive –Negative = Positive  Difference in Charges Examples: –Water –Ammonia

(9) Chemical Reactions Chemical Reaction = Interaction of atoms’ valence electrons. –Breaking of bonds –Rearranging of atoms –Forming of bonds –Release / Store Energy Happens when atoms are unstable (empty valence shell)!

(10) Energy Chemical Reactions = Conversion & Transfer of Energy Kinetic = Energy of Motion OR Energy Being Used –Break Bonds = Stored Energy becomes Kinetic –Form Bonds = Kinetic Energy stored in Bonds Potential = Stored Energy –Break Bonds = Release Potential Energy –Form Bonds = Store Work-Energy in Bonds