Teaching replication, transcription, and translation is a challenge for undergraduate students and teachers due to the abstract and multi-step processes. This study examined an active learning activity supported by artificial intelligence designed to improve conceptual understanding in an undergraduate Nutrigenetics course. Using a qualitative phenomenological approach, 23 students completed a mission-style worksheet on these molecular processes, verified each step with an AI assistant (ChatGPT, GPT-5), and submitted individual reflective responses. Data were analyzed through inductive thematic analysis. Four main themes emerged during the analysis: (1) Cognitive task complexity and conceptual challenges; (2) Detection of inconsistencies through self-monitoring; (3) AI-mediated feedback and critical evaluation of AI output; (4) Motivation and engagement in the mission-style activity. Students described clearer understanding of sequence orientation, RNA splicing, codon alignment, and the interdependence of DNA-RNA-protein processes. AI feedback supported clarification of misconceptions, while inaccuracies encouraged students' critical thinking. Overall, the activity increased engagement, conceptual integration, and reflective learning. These findings suggest that AI-supported active learning can increase molecular biology instruction in health science programs. Further research should include longitudinal designs and performance-based assessments.
