Proteins are chains of amino acids that fold into specific three-dimensional shapes. Occasionally, these folded proteins interact to create complexes composed of identical or different subunits. What term describes this type of protein assembly?

Explanation

The correct answer is quaternary structure, which refers to the arrangement of multiple folded protein subunits into a larger functional complex. Denatured state means unfolded protein, molecular aggregation and precipitation involve non-specific clumping, and secondary structure describes local folding patterns like alpha helices and beta sheets.