In enzymology, an alpha,alpha-trehalose phosphorylase is an enzyme that catalyzes the chemical reaction alpha,alpha-trehalose + phosphate ⇌ {\displaystyle \rightleftharpoons } alpha-D-glucose + alpha-D-glucose 1-phosphateThus, the two substrates of this enzyme are alpha,alpha-trehalose and phosphate, whereas its two products are alpha-D-glucose and alpha-D-glucose 1-phosphate. Wikipedia