Cellular Respiration Notes

Cellular Respiration Notes - Cellular Respiration ATP is a...

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Cellular Respiration ATP is a high energy molecule. The reason for this is because it has 3 phosphates attached to it and they all repel each other because they all have negatively charged oxygen atoms. This repulsion makes the bond weak and less energy is required to break these weak bonds. As a result, less energy can be used to break the bonds and allows us to make even stronger bonds. This gives us a profit of ATP and thus, ATP is a higher energy molecule. Two types of energy transfer mechanisms: substrate-level phosphorylation and oxidative- phosphorylation. Substrate-level Phosphorylation: ATP is formed directly by enzyme-catalyzed reactions A phosphate containing compound like phosphoenolpyruvate (PEP) transfers a phosphate group directly to ATP, forming ATP During this process, only 31 kJ/mol of energy is transferred Oxidative-phosphorylation: ATP is formed indirectly Its called oxidative because it involves a number of sequential redox reactions with oxygen being the final acceptor Yields more ATP molecules than substrate-level phosphorylation This process begins with nicotinamide adenine dinucleotide (NAD+) which removes two hydrogen atoms (contains 2H+ and e-) The two H+ and electrons combined with the NAD + and reducing it to NADH 2 A dehydrogenase enzyme catalyzes this reaction in step 6 of Kreb’s Cycle Another coenzyme called flavin adenine dinucleotide (FAD) performs a function similar to NAD+ It grabs 2 H+ and 2 e and is reduced to FADH2 in one of the steps in Kreby’s cycle The reduced coenzymes act as mobile energy carrierss within the cell, moving free energy from one place to another and from one molecule to another Go from glucose to pyruvate to oxidation and reduction of H+ and electrons in the electron transport chain, finally ATP is produced about 34 by oxidative phosphorylation
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Enzymes: 1. Kinase: adds or removes a phosphate from a molecule. It is used in glycolysis on glucose and other sub-molecules from glucose. With the help of kinase, ATP is added to a glucose molecule. This causes the weakening of the bonds in the molecule and this allows the molecule to be more easily broken down. As a result, it can cause the release of energy later on in glycolysis. If kinase is inhibited, the whole process of glycolysis stops because the bonds cannot be weakened. As well, by adding a phosphate to a glucose molecule, it allows the glucose molecule to stay within the cytoplasm and not leave the cell. 2. Isomerase: converts one molecule to an isomer. In step 2 of glycolysis, glucose 6- phosphate is converted into fructose-6-phosphate. This makes the molecule more symmetrical and it is easier to break down fructose than glucose. If this was inhibited, glycolysis cannot continue since glucose cannot be converted to fructose. 3.
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Cellular Respiration Notes - Cellular Respiration ATP is a...

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