Shivani Patel Lecture 16 Glycolysis 1A What is an oxidation reduction reaction Pg 164 1st column 1st paragraph The oxidation reduction reaction redox reactions is the transfer of electron s from one reactant to another Oxidation is when substance loses electrons Reduction is when substance gains an electron 1B In the oxidation reduction reaction shown below which reaction component is the reducing agent and which is the oxidizing agent C6H12O6 6 O2 6 CO2 6 H2O Energy ATP heat The oxygen is being reduced oxidizing agent If its being reduced then it acts as the oxidizing agent in the reaction Electron acceptor The glucose is being oxidized reducing agent If its being oxidized then it acts as the reducing agent in the reaction Electron donor 2A How is the formation of a polar covalent bond an example of an oxidation reduction reaction Pg 164 Figure 9 3 Polar covalent bonds are formed when there is an atom that has a high electronegativity This atom then pulls on the other atoms and the atoms being pulled on lose electrons which causes oxidation reduction reaction to occur 2B How does the potential energy in an electron relate to its association with an electronegative atom Pg 164 paragraph 4 An electron loses potential energy when it is moved from a less electronegative atom to a more electronegative atom just like a ball rolling down a hill loses potential energy because its position is going down 3 What are the roles of dehydrogenase and the coenzyme nicotinamide adenine dinucleotide NAD in catabolic pathways Pg 165 paragraphs 2 3 The role of coenzyme nicotinamide adenine dinucleotide NAD in catabolic pathways is that it can easily cycle between oxidized NAD and reduced NADH states which allows it to act as an electron carrier electron carriers needed when glucose is being catalyzed In order for NAD to be trap electrons from glucose a dehydrogenase is needed A dehydrogenase removes a pair of hydrogen atoms 2 electrons and 2 protons from substrate e g glucose thereby oxidizing it The enzyme then delivers the 2 electrons and 1 proton to its coenzyme NAD The extra proton is released into the surrounding as a hydrogen H ion Since NAD receives 2 electrons and only 1 proton it becomes reduced to NADH Shivani Patel 4 What is the advantage of a controlled release of energy as electrons are carried toward an electronegative Oxygen atom Pg 166 Fig 9 5 The advantage of controlled release of energy as electrons are carried toward an electronegative oxygen atom is that the energy released is used while the electrons cascade down from one carrier molecule to another losing small amounts of energy at a time until oxygen is reached which is the terminal electron acceptor In an uncontrolled release of energy the energy is released and causes an explosion basically a waste of energy 5 Define substrate level phosphorylation One sentence Pg 167 Fig 9 7 Substrate level phosphorylation is a mode of ATP synthesis where an enzyme transfers a phosphate group from a substrate molecule straight to the ADP molecule rather than adding an inorganic phosphate to ADP as an oxidative phosphorylation Ex Occurs in glycolysis steps 7 and 10 Substrate molecule refers to an organic molecule generate as an intermediate during catabolism of glucose 6A How does the energy investment phase of glycolysis differ from the energy pay off phase Describe the products of glycolysis in your answer Pg 168 Fig 9 8 In the energy investment phase 2 ATPs are used and converted to 2 ADP and 2 phosphates In the energy pay off phase the investment made in the first phase is paid off because 4 ATPs are created by substrate level phosphorylation Furthermore NAD is reduced to NADH by electrons released from the oxidation of glucose The net energy yield from glycolysis per glucose molecule consist of 2 ATP and 2 NADH Other products created are 2 pyruvate and 2 water molecules 6B What is the fate of the final product of glycolysis Pg 169 2nd paragraph and Fig 9 10 The final product pyruvate a charged molecule first enters the mitochondria through active transport The pyruvate then is converted into a compound called acetyl coenzyme acetyl CoA entry compound in the citric cycle during cellular respiration The pyruvate dehydrogenase complex catalyzes the 3 steps of oxidation of pyruvate to acetyl CoA 7 What is the donor of the H ion donated to NAD when pyruvate enters the mitochondrial matrix Lecture notes and Slide 15 FADH2 donate H ions to NAD when pyruvate enters the mitochondrial matrix 8 List four vitamins that play a direct role in glycolysis and the citric acid cycle Lecture notes and Slides 14 15 Vitamin B thiamin pantothenic acid riboflavin and niacin Shivani Patel