Course-based Undergraduate Research Experiences (CUREs) are a pedagogical model where a traditional undergraduate course is transformed into a research-intensive course, offering an alternative pathway to research for undergraduate students. Given the novel learning context of CUREs, there is a need to understand the learning that occurs and the impact of social interactions on students in defining and managing the socially negotiated understandings and practices of the science research laboratory. This manuscript reports the findings from a qualitative study of students enrolled in a CURE sequence that bridged a lower-division organic chemistry laboratory with an upper-division quantitative analysis laboratory. Communities of practice are groups of people who share a common objective or seek to address a common problem, characterized by three elements, domain, community, and practice. The design elements identified for CUREs, research practices, discovery, relevance, collaboration, and iteration, can be aligned with the three elements of CoP to provide a lens to make sense of the learning that occurs in this novel context. Focus groups consisting of 3-5 students each were conducted with students participating in two cohorts (N = 65) of the CURE sequence during the last week of the academic term. In addition, semistructured interviews were conducted with CURE faculty. Thematic analysis of the interview data derived three themes: "working toward a common goal, addressing obstacles," and "developing a deeper understanding of the science content." The alignment of the themes with the Lave and Wenger's Community of Practice (CoP) Framework is described and provides the basis for applying CoP to research on CUREs.