In enzymology, a phosphatidylinositol-4,5-bisphosphate 3-kinase is an enzyme that catalyzes the chemical reaction: ATP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate ⇌ {\displaystyle \rightleftharpoons } ADP + 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphateThus, the two substrates of this enzyme are ATP and 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate, whereas its two products are ADP and 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate. Wikipedia