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Cells and Energy Slide 2 Mitochondria Slide 3 Adenosine Triphosphate Slide 4 ATP ATP is the chemical energy "currency" of the cell that powers the cell's metabolic activities ATP is used To transport materials throughout the cell and across the cell membrane To provide energy for basic functions carried out by all parts of the cell Slide 5 Energy Production There are two ways a cell can obtain energy from food: fermentation and cellular respiration. Both start with the same first step Glycolysis: the breakdown or splitting of glucose (6 carbons) into two 3-carbon molecules called pyruvic acid Slide 6 Glycolysis is found in all living organisms. occurs in the cytoplasm of cells does not need oxygen as part of any of its chemical reactions. serves as a first step in a variety of both aerobic and anaerobic energy-harvesting reactions. http://www.northland.cc.mn.us/biology/Biology1111/a nimations/glycolysis.html http://www.northland.cc.mn.us/biology/Biology1111/a nimations/glycolysis.html Slide 7 Anaerobic Respiration Without Oxygen Slide 8 Fermentation: In fermentation, pyruvic acid molecules are converted into energy net production of two ATP molecules per molecule of glucose four ATP are produced in glycolysis, but two get used up in the process) two most common types: lactic acid fermentation alcohol fermentation. Slide 9 lactic acid fermentation muscles normally perform cellular respiration when O 2 is present (aerobic respiration). During exhaustive exercise when O 2 supply cannot keep up with the demand, muscle cells switch to lactic acid fermentation (anareobic respiration). Slide 10 lactic acid fermentation pyruvic acid molecules are turned into lactic acid, which builds up in the muscles making them stiff and sore. l.a. will eventually be removed and taken to the liver by the blood where it is taken out of circulation Slide 11 Alcohol fermentation Alcohol fermentation is carried out by yeast and some bacteria. The waste products of this process are ethanol and carbon dioxide (CO 2 ). Used in making making bread, beer, and wine. Bread: CO 2 forms and is trapped between the gluten (a long protein in wheat) molecules that causes the bread to rise, and the ethanol evaporating gives it the classic smell while baking. Slide 12 Cellular Respiration Slide 13 Aerobic Respiration With Oxygen Slide 14 Cellular Respiration There are three steps in the process of cellular respiration: 1.Glycolysis (cytoplasm) 2.Krebs cycle (Matrix) 3. electron transport chain (Inner Membrane) Slide 15 Glycolysis Slide 16 Mitochondria Slide 17 the power house of the cell that converts oxygen and nutrients into ATP (adenosine triphosphate). Structure Outer membrane: protective layer Inner membrane site of the electron transport chain (a series of electron carriers) Slide 18 Cellular Respiration Electron Transport Chain Slide 19 Slide 20 Mitochondria Intermembrane space: space into which H+ ions get pumped into Cristae: The infoldings of the inner membrane that increase surface area (increases the productivity of C.R.) Matrix: space where Krebs cycle runs, contains many enzymes used in Krebs Slide 21 Krebs Cycle (citric acid cycle) Slide 22 Electron Transport Chain Slide 23 Slide 24 Energy Summary