Answer:
The three-dimensional shape of the protein
Explanation:
Proteins are one of the four major biological molecules in nature (others being carbohydrates, lipids, and nucleic acids). Proteins are polymers containing monomers called AMINO ACIDS, which happen to be 20 in number.
Proteins serve as enzymes, transport proteins functionally as stated in this question. This specificity in function is attributed to the 3-dimensional structure or shape that a protein molecule forms as a result of the amino acids present in it. The type of amino acids in an enzyme determines how it'll fold up into the three-dimensional structure that determines its function.