GRT Task 4
Hereditary Fructose Intolerance
Two features that make all enzymes catalysts:
Enzymes are proteins that act as catalysts. A catalyst speeds up the rate of the reaction. Enzymes and catalysts do not affect the equilibrium constant. Enzymes and chemical catalysts increase the rate of a reaction in forward and reverse directions. Enzymes and catalysts bind their substrates for a brief period of time. The active site is the part that binds the substrate and carries out catalysis (cliffnotes.com, n.d.).
How enzymes act as protein catalysts in fructose metabolism in the liver:
Enzymes are involved in the metabolism of fructose. Fructolysis happens when fructose first enters the body and initial catabolism of fructose takes place. The metabolism of fructose starts with an enzyme called fructokinase. Fructokinase is an enzyme that is found in the liver. Fructokinase produces F1P. Next, an enzyme named aldolase B will convert the F1P into dihydroxyacetone phosphate and glyceraldehyde. The body will use these enzymes to get rid of energy. The body could not get rid of fructose without these two enzymes (cliffnotes.com, n.d.).
Substrate acted on by aldolase B:
Aldolase B can use F-1, 6-BP and F1P as substrates. F1P is a derivative of fructose. It is produced in the liver by fructokinase (ghr.nlm.nih.gov, n.d.).
The role of aldolase b during the metabolism of fructose:
Aldolase b is required for the breakdown of carbohydrates. It acts as a catalyst in the glycolytic-gluconeogenic pathway. The metabolism of fructose also requires aldolase b. After fructose is absorbed it is phosphorylated by fructokinase to form F1P. Aldolase B then acts to catalyzes F1P breakdown into glyceraldehyde and DHAP. Glyceraldehyde is phosphorylated by triose kinase to form G3P. Both products are used in the glycolytic-gluconeogenic pathway. They can be modified to become either glucose or pyruvate (ghr.nlm.nih.gov, n.d.).
Products of aldolase B...