In this work, we describe new strategies for scheduling and executing Workflow applications on Grid resources us- ing the GrADS [18] infrastructure. Workflow scheduling is based on heuristic scheduling strategies that use applica- tion component performance models. The Workflow is exe- cuted using a novel strategy to bind and launch the appli- cation onto heterogeneous resources. We apply these strate- gies in the context of executing EMAN, a Bio-imaging work- flow application, on the Grid. The results of our experi- ments show that our strategy of performance model based, in-advance heuristic workflow scheduling results in 1.5 to 2.2 times better makespan than other existing scheduling strategies. This strategy also achieves optimal load balance across the different Grid sites for this application.