1. Many reactions involve the passage of electrons from one atom/molecule to another Oxidation is the loss of electrons (“LEO”) Reduction is the gain of electrons (“GER”) Oxidation-reduction reactions always take place together Note that the transfer of electrons through these redox reactions is a transfer of energy Zn is oxidized as it donates electrons to O to reduce it. Note the counterintuitve part that O is reduced by gaining e-. Movie animation of ReDox Energy transfer between molecules: Oxidation- Reduction reactions

2. Redox reactions occur in pairs. We start with two compounds, A and B. A has the ability to give up an e -, while simultaneously, B has the ability to take on an e -. Loss of electron (oxidation) A* + e–e– BA B* _ Gain of electron (reduction) Low energy High energy Next, A can take on an e -, and become “reduced” and B can give up it’s e - be “oxidized.”

3. A is in the oxidized or reduced state? And B? Incoming electron from a nearby atom or compound brings with it energy. When associated with A, A has absorbed or gained energy, energy has been transferred to it. C C pulls B’s extra electron from it, thus gaining energy, by transfer from B, to become neutral

4. Read more: http://science.jrank.org/pages/4963/Oxidation-Reduction-Reaction- Current-future-uses.html#ixzz0O6KtePVQ Photosynthesis, the conversion of light to chemical energy by plants, is a form of oxidation-reduction reaction that produces two essentials of human life: oxygen and carbohydrates. Cellular respiration, which along with photosynthesis is an oxidation-reduction reaction in which living things break down molecules of food to produce energy, carbon dioxide, and water. Burning, batteries, metallurgy, and photography all rely on oxidation-reduction reactions. An important application of oxidation-reduction reactions is in electrochemical cells Oxidation-reduction reactions can be used for bleaching materials and sanitizing water Oxidation - Reduction Reactions: in Living or Non-living systems ??? BOTH :

5. A catalyst provides an alternative route for the reaction with a lower activation energy. EnzymesEnzymes in the human body regulate oxidation-reduction reactions. These complex proteins, of which several hundred are known, act as catalysts, speeding up chemical processes in the body. Oxidation-reduction reactions also take place in the metabolism of food for energy, with substances in the food broken down into components the body can use.