2. Now let us see what you have learned thus far!

3. Recall cellular respiration is… a series of controlled biochemical reactions involved in the conversion of chemical potential energy to usable energy stored in the bonds of ATP both exothermic and catabolic occurring initially in the cytosol followed by mitochondria Comprised of a reaction mechanism consisting of four reaction series 1.Glycolysis 2.pyruvate oxidation 3.Kreb’s cycle 4. Electron Transport System

4. Before profiling each of these reaction series we need to learn about the many different reaction types that will be occurring!

5. Hydrolysis … the addition of a molecule of water, in an attempt to convert a complex structure to a simpler one the water molecule cleaves the specific linkage and re-establishes the functional groups Hydrolysis vs Hydration Hydration … the addition of a molecule of water to increase hydrogen and oxygen count there is no bond/linkage cleavage

6. Condensation … removal of a water molecule in an attempt to form a linkage between adjacent functional groups Results in an increase in the complexity of the structure Condensation vs Dehydration Dehydration … removal of a water molecule in an attempt to reduce oxygen and hydrogen atom counts structure complexity is maintained

7. Phosphoryl Shift… Dephosphorylation … the removal of a phosphate group from a molecule generally results in the release of energy if ATP is dephophorylated Dephosphorylation and Phosphoryl Shift the movement of a phosphate group from one position to another within the same molecule carbon numbering will indicate location

8. Decarboxylation, Isomerization and Redox Reactions Decarboxylation … the removal of a carbon dioxide group to reduce carbon count Isomerization … rearrangement of atoms within a molecule to generate an isomer of the original molecule Remember isomers have the same molecular formula but different structural configurations

9. Redox (oxidation and reduction)… transfer of electrons between molecules, one molecule is oxidized (lose electrons) and one is reduced (gain electrons) usually involves the energy carrier molecules NAD (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide) in cellular respiration, these redox reactions hold the released energy of the exothermic reaction as the substrate is oxidized and the energy carrier is reduced

10. As previously mentioned, the most important goal of cell respiration is to capture as much free energy as possible from the exothermic reactions in the form of ATP. This requires a phosphorylation (addition of a phosphate group) to an ADP molecule There are 2 main ways to capture this energy as ATP and allow for the necessary phosphorylation: 1.Substrate level phosphorylation 2.Oxidative phosphorylation

11. 1.Substrate level phosphorylation ATP is formed directly in an enzyme catalyzed reaction a phosphate, from a phosphate containing compound, is transferred to ADP to form ATP and usable energy is trapped in that phosphate bond ADPATP compound P

12. 2.Oxidative Phosphorylation ATP is formed indirectly process involves a number of sequential redox reactions, with oxygen as the final electron acceptor reduced coenzymes FADH and NADH act as energy carriers which eventually transfer their energy into ATP via oxidative phosphorylation

13. Energy Carriers Remember cellular respiration …  is a highly exothermic reaction ( http://vimeo.com/7540630 )  has many individual reactions within the process that are exothermic as well. energy released in these reactions must be captured and stored in appropriate energy carrier molecules ATP When little energy is released, it is stored as ATP FADH When a medium amount of energy is released, it is stored as FADH and eventually produces 2 ATP molecules NADH When a large amount of energy is released, it is stored as NADH and eventually produces 3 ATP molecules

14. Cellular Respiration Overview 1.Glycolysis 2.Pyruvate Oxidation 3.Krebs Cycle 4.Electron Transport and Chemiosmosis As we go, remember that cellular respiration is an exothermic, catabolic process. Refer to your textbook pages 94-115! There are 4 reaction sequences occurring in the overall process each with their own unique location, reactants, products and goal. Always remember that the product of one step in a reaction series is the reactant of the next!

15. Now let us see focus on the glycolytic pathway of cellular respiration!