Using a qualitative case study method, we examined how students talked, acted, and felt in structured inquiry in attempt to understand how students' epistemic emotions interact with their engagement in practices. Participants were four 5th graders, and data included audio recordings of the students' talk in structured inquiry for learning a biology-related unit, the teacher's field notes, and interviews with the students. The data were analysed qualitatively with foci placed on the variations in the students' epistemic emotions and their interactions with practices. It was revealed that the students felt a variety of positive and negative epistemic emotions and shaped their practices in response to these emotions. More specifically, the students' epistemic curiosity and joy facilitated their continuous focus on inquiry tasks and taking a positive attitude towards inquiry. In addition, epistemic confusion and anxiety helped students felt helped them find alternative ways to perform their inquiry and prepare a better presentation of their learning. It was concluded that epistemic emotions and practices interacted with each other to shape students' words and behaviours as they learned science. Additionally, it was also suggested that epistemic emotions can positively contribute to the development of students' conceptual understanding of science.