BIOL 201 Study Guide - Final Guide: Dihydroxyacetone, Enzyme Catalysis, Triose
Document Summary
Lowers intracellular glucose concentration to allow further uptake. Nucleophilic oxygen at c6 of glucose attacks the last ( ) phosphate of atp. Atp-bound mg 2+ facilitates this process by shielding the negative charges on atp. C1 of fructose is easier to phosphorylate by pfk. An aldose (glucose) can isomerize into a ketose (fructose) via an enediol intermediate. The isomerization is catalyzed by the active-site glutamate, via general acid/base catalysis. Allows for 1 phosphate/3-carbon sugar after step 4. First committed step of glycolysis fructose 1,6-bisphosphate is committed to become pyruvate and yield energy. Do not burn glucose if there is plenty of atp. Cleavage of a six-carbon sugar into two three-carbon sugars. The reverse process is the familiar aldol condensation. Fungal and bacterial aldolases employ metal ion catalysis. Gap concentration kept low to pull reaction forward. Only gap is the substrate for the next enzyme.
