Life science research is becoming evermore computationally intensive. Hence, from a computational resource perspective, Grid computing provides a logical approach to meeting many of the computational needs of life science research. However, there are several barriers to the widespread use of Grid computing in life sciences. In this paper, we attempt to address one particular barrier: the difficulty of using Grid computing by life scientists. Life science research often involves connecting multiple applications together to form a workflow. This process of constructing a workflow is complex. When combined with the difficulty of using Grid services, composing a meaningful workflow using Grid services can present a challenge to life scientists. Our proposed solution is a Semantic Web-enabled computing environment, called Bio-STEER. In Bio-STEER, bioinformatics Grid services are mapped to Semantic Web services, described in OWL-S. We also defined an ontology in OWL to model bioinformatics applications. A graphical user interface helps to construct a scientific workflow by showing a list of services that are semantically sound; that is, the output of one service is semantically compatible with the input of the connecting service. Bio-STEER can help users take full advantage of Grid services through a user-friendly graphical user interface (GUI), which allows them to easily construct the workflows they need.