Answer:
Tertiary Structure
Explanation:
Proteins are made up of amino acid units. The four types of protein structure are primary, secondary, tertiary, and quaternary.
From the given options, the greatest effect on a protein's function is caused by tertiary structure because it has branched structure and have several side chains. These side chains can interact in different ways and can change the effect on a protein's function.
Hence, the correct answer is "Tertiary Structure".