The phrase refers to the search for a compilation, typically in a portable document format (PDF), that contains a large number of solved questions related to the field of biochemistry, and which is available for acquisition without cost. Such a resource would presumably offer users a way to test their understanding of biochemical principles and problem-solving abilities.
Access to such materials can be highly beneficial for students and professionals in related scientific disciplines. They can serve as valuable study aids for exam preparation, as well as tools for self-assessment and knowledge reinforcement. Historically, students relied on textbooks and instructor-provided materials for practice questions. The rise of the internet and digital document formats has increased the accessibility of practice question sets, including those offered without charge.