(7)+Cellular+respiration+-+the+process

(1) Cellular respiration – The process (this is your most difficult topic – put good students on it) > We digest food because our body needs to break down water and nutrients so that they can be transported into cells and used for respiration. > Where does cellular respiration occur: > Cellular respiration occurs in the mitochondria of the cell, the organelle in the cell which gives the cell energy to do things like active transport.
 * Recap: why do we digest:

Cellular respiration **requires** organic food molecules. Aerobic respiration requires oxygen, unlike anaerobic, which doesn't require oxygen. Cellular respiration produces energy, most commonly in the form of ATP (adenosine triphosphate) **The four steps of cellular respiration** are glycolysis, oxidation of pyruvate, the Krebs cycle and the electron chain.
 * Glycolysis **

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Glycolysis occurs in cytosol. During glycolysis, 6-carbon sugar, glucose, is broken down into two molecules of a 3-carbon sugar, pyruvate; this change is accompanied by a net gain of two ATP molecules and 2 NADH molecules. 1) Two phosphates are added to the glucose molecule; as a byproduct, two ATP (adenosine triphosphate) molecules are converted into two ADP (adenosine diphosphate, low energy) molecules. A 6-carbon sugar diphosphate molecule is formed. 2)The 6-carbon sugar diphosphate molecule is then split into two 3-carbon sugar phosphate molecules. 3) These two 3-carbon sugar phosphate molecules are converted through a series of steps into pyruvate. During these reactions, electrons are transferred to coenzyme NAD+ to form NADH and ATP is formed from ADP. Pyruvate oxidation occurs in the inner membrane of the mitochondria.  1) The pyruvate is oxidized (it goes from 3C to 2C acetyl. CO2 is released as a result). 2) NAD+ is reduced to NADH 3) the pyruvate dehydrogenase complex attaches CoA to acetyl. []
 * Oxidation of pyruvate **
 * The Krebs Cycle **
 * The electron transport chain **

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During anaerobic respiration, food molecules are only partly broken down, **because oxygen is required to completely break down food molecules**; **much less energy is available to the cell from each food molecule in anaerobic respiration in comparison to aerobic respiration**. Aerobic respiration yields about twenty times more energy than anaerobic respiration. "Glycolysis " Anaerobic Respiration. Web. 27 Oct. 2011. media type="youtube" key="2f7YwCtHcgk" height="315" width="560"

media type="youtube" key="3wCGkmfEV9I" height="315" width="420" <[|http://www.anaerobicrespiration.net/general/glycolysis-and-anaerobic-respiration/#more-37]> "Equation of Anaerobic Respiration." Anaerobic Respiration. Web. 27 Oct. 2011. <[|http://www.anaerobicrespiration.net/general/equation-of-anaerobic-respiration/#more-35]> "Cell Respiration: Introduction." Prentice Hall Bridge Page. Web. 27 Oct. 2011. <[]> "Animation: Electron Transport System and ATP Synthesis (Quiz 1)." Your Page Title. Web. 27 Oct. 2011. <[]> "Animation: How Glycolysis Works." Your Page Title. Web. 27 Oct. 2011. <[]> "Pyruvate Dehydrogenase & Krebs Cycle." Rensselaer Polytechnic Institute (RPI) :: Architecture, Business, Engineering, IT, Humanities, Science. Web. 27 Oct. 2011. <[]>