'Structure' and 'function' are both ambiguous terms. Discriminating different meanings of these terms sheds light on research and explanatory practice in molecular biology, as well as clarifying central theoretical concepts in the life sciences like the sequence-structure-function relationship and its corresponding scientific "dogmas". The overall project is to answer three questions, primarily with respect to proteins: What is structure? What is function? What is the relation between structure and function? The results of addressing these questions lead to an answer to (...) the title question, what the statement 'structure determines function' means. (shrink)