Cassady sandbox1: Difference between revisions
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==Regulation== | ==Regulation== | ||
Glycolysis is an essential metabolic process for survival. Therefore, in its activation and suppression it must be highly regulated. Three points in the process of glycolysis occur with a large negative free energy and are therefore, irreversible. These three points are hexokinase, phosphofructokinase, and pyruvate kinase. These three reactions are candidates to be the major points of regulation because of their high negative free energies. Of the three PFK is considered the major regulatory point for glycolysis (#3 in the picture below) in muscle with a ΔG= -25.9 kJ/mol, because it is a committed step. Once PFK converts F6P to F1,6P, the reaction will not be easily reversed because of the high | Glycolysis is an essential metabolic process for survival. Therefore, in its activation and suppression it must be highly regulated. Three points in the process of glycolysis occur with a large negative free energy and are therefore, irreversible. These three points are hexokinase, phosphofructokinase, and pyruvate kinase. These three reactions are candidates to be the major points of regulation because of their high negative free energies. Of the three, PFK is considered the major regulatory point for glycolysis (#3 in the picture below) in muscle, with a ΔG= -25.9 kJ/mol, because it is a committed step. Once PFK converts F6P to F1,6P, the reaction will not be easily reversed because of the high amount of energy that must be overcome to go backward. <ref>Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry: Life at the Molecular Level. Hoboken, NJ: Wiley, 2008. Print.</ref>. This energy barrier makes sense seeing as pyruvate kinase catalyzes the final reaction (#10) and hexokinase (#1) is not involved in glycolysis at all when the process is begun from glycogen.<ref>Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry: Life at the Molecular Level. Hoboken, NJ: Wiley, 2008. Print.</ref> | ||
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