Describe the difference bettween a kinase and a phosphatase. Solution Kinase Phosphatase catalyze the phosphorylation reactions by the addition of phosphate groups from ATP to protein molecules. catalyze the dephosphorylation reactions by removing of phosphate groups from substrates. The phosphorylation reaction is unidirectional The dephosphorylation reaction is bidirectional Kinase uses ATP to obtain phosphate groups Phosphatase use water molecules to remove phosphate groups Proteins that are activated by a kinase Proteins deactivated by a phosphatase. Kinase Phosphatase catalyze the phosphorylation reactions by the addition of phosphate groups from ATP to protein molecules. catalyze the dephosphorylation reactions by removing of phosphate groups from substrates. The phosphorylation reaction is unidirectional The dephosphorylation reaction is bidirectional Kinase uses ATP to obtain phosphate groups Phosphatase use water molecules to remove phosphate groups Proteins that are activated by a kinase Proteins deactivated by a phosphatase..