Creative exercises (CEs), a specific form of open-ended assessment tools, have been shown to promote students' linking of prior and newly learned concepts within a course. In this study, we examined how often students in an upper-division undergraduate biochemistry course linked prior chemical concepts to biochemical ones in response to CE prompts. Thematic analysis of participant responses showed students making in response to the CEs multiple connections between prior chemical concepts and biomolecule structure, thermodynamics and enzyme kinetics. In the case of thermodynamics and enzyme kinetics CEs, most students tended to rely on contexts and concepts focused on specific materials from their current course whereas responses to biomolecule structure CEs mostly invoked foundational concepts in acid--base and organic chemistry, such as pH/pKa, pI, ionization, stereochemistry, and organic functional groups. Invoking the cognitive resources activation framework in discussing the findings, we highlight the utility and relevance of CEs in upper division courses that rely on the application of prior chemical knowledge to explain new ones as well as the implications of the findings for research and teaching.