Electron+Transport+Chain

** Electron Transport ** ** Chain ** (Involving Oxygen) || || 32 ATP || || 6 H2O (waste) || [|ETC Diagram] The **electron transport chain (ETC)** uses the eight NADH and the two FADH2 that are produced in the Krebs cycle (along with oxygen) to create thirty-two ATP and six H2O. The main purpose of the ETC is to synthesize ATP. During this cycle, hydrogen atoms are separated into electrons and protons. The process takes place mostly in and around the inner membrane of the mitochondria. This is because the enzymes and proteins needed for the ETC are embedded in the inner membrane. The proteins and enzymes are called **cytochromes** and are easily reduced and oxidized. Similar to the traveling of electrons between the photosystems of a plant, the electrons are passed from one cytochrome to the next until it reaches the terminal cytochrome. The **terminal cytochrome** then attaches the electrons and protons to oxygen and produces water. However, like the electrons traveling between a plants photosystems, the traveleing electron of the ECT also serve a purpose while moving from one cytochrome to the next. While the electrons travel, they release some free energy which is used to actively transport the protons from the matrix to the intermembrane space. When the concentration gradiant becomes too high, the protons flow back into the matrix through a special structure. This special structure uses the energy released by the moving protons to turn ADP and phosphate groups into ATP. Most bacteria have the ETC on their cell membranes. Bacteria called **faculative aerobes** can survive long periods of time without oxygen because they can switch between being aerobic and anaerobic. They use sulfate or nitrate instead of oxygen and produce sulfide or ammonia respectively. Some bacteria are called **obligate anaerobes** because they cannot survive in the presence of oxygen. Others are called **obligate aerobes** because they cannot survive without the presence of oxygen. [|Mitochondria Inner Structure Diagram Source] link to video: [|Cellular Respiration (Electron transport chain)] (uses specific names and does not cover everything)  Sources of Information:   BSCS. "5.6 The Electron Transport System." BSCS. __BSCS Biology A Molecular Approach.__ 8 (blue version). New York: Glencoe McGraw-Hill, 2001. 139-142.
 *  **In** || **Out**
 * 8 NADH + 2 FADH2 (from Kreb's cycle)
 * 3 O2
 * **Molecule** || **# of ATP Produced for Each** ||
 * NADH || 3 ||
 * FADH2 || 2 ||