phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate and represents the key control point in mammalian glycolysis. The enzyme is a homotetramer that is inhibited by ATP binding, activated by AMP binding, negatively regulated by phosphorylation, and competitively inhibited by 2,5-anhydro-D-glucitol-1,6-diphosphate. (a) Would you expect a plot of the initial rate of fructose 1,6-bisphosphate formation as a function of substrate concentration to show a sigmoidal or hyperbolic curve? (b) How would each of the regulators above affect the dynamics of the T state to R state equilibrium of phosphofructokinase? Briefly explain your reasoning. (c) If it were possible to isolate phosphofructokinase monomers in an active form, how would you expect the kinetics in (a) to be affected? How would the rate of the reaction be affected by ATP, AMP, and 2,5-anhydro-D-glucitol-1,6-diphosphate? Briefly explain your answers.
Enzyme kinetics
In biochemistry, enzymes are proteins that act as biological catalysts. Catalysis is the addition of a catalyst to a chemical reaction to speed up the pace of the reaction. Catalysis can be categorized as either homogeneous or heterogeneous, depending on whether the catalysts are distributed in the same phase as that of the reactants. Enzymes are an essential part of the cell because, without them, many organic processes would slow down and thus will affect the processes that are important for cell survival and sustenance.
Regulation of Enzymes
A substance that acts as a catalyst to regulate the reaction rate in the living organism's metabolic pathways without itself getting altered is an enzyme. Most of the biological reactions and metabolic pathways in the living systems are carried out by enzymes. They are specific for their works and work in particular conditions. It maintains the best possible rate of reaction in the most stable state. The enzymes have distinct properties as they can proceed with the reaction in any direction, their particular binding sites, pH specificity, temperature specificity required in very few amounts.
phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate and represents the key control point in mammalian glycolysis. The enzyme is a homotetramer that is inhibited by ATP binding, activated by AMP binding, negatively regulated by phosphorylation, and competitively inhibited by 2,5-anhydro-D-glucitol-1,6-diphosphate.
(a) Would you expect a plot of the initial rate of fructose 1,6-bisphosphate formation as a function of substrate concentration to show a sigmoidal or hyperbolic curve?
(b) How would each of the regulators above affect the dynamics of the T state to R state equilibrium of phosphofructokinase? Briefly explain your reasoning.
(c) If it were possible to isolate phosphofructokinase monomers in an active form, how would you expect the kinetics in (a) to be affected? How would the
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