Final answer:
Changes in the primary structure of a protein can significantly impact its tertiary structure. The sequence of amino acids in the primary structure dictates the folding patterns leading to the functional three-dimensional shape. So the correct option is C.
Step-by-step explanation:
Small changes in primary protein structure may lead to big changes in tertiary protein structures. The correct answer is C: primary; tertiary.
The primary structure of a protein refers to its unique sequence of amino acids. Changes to this sequence can alter the way in which the protein folds, which is a crucial aspect of its secondary structure, such as the formation of alpha helices and beta sheets. This, in turn, significantly affects the tertiary structure, which is the overall three-dimensional folding pattern due to side chain interactions among these secondary structures. It is this tertiary structure that determines the protein's function and specificity.
Therefore, alterations in the primary structure can have far-reaching effects, potentially disrupting the protein's ability to function correctly, which may lead to various biological malfunctions or diseases.