What determines the function of a protein?

Correct answer: C) The protein’s specific structure.
The function of a protein is determined by its unique three-dimensional structure, which is determined by the sequence of amino acids and the interactions between them. The specific arrangement of amino acids in space allows the protein to bind to specific molecules, catalyze chemical reactions, or perform other functions.

The structure of a protein determines its function because it creates a specific binding site or active site that allows the protein to interact with other molecules. This is often referred to as the "lock and key" model, where the protein's structure provides a specific shape that allows it to bind to a particular molecule.

The other options are not correct because:
A) The number of peptide bonds is related to the length of the protein, but not its function.
B) The types of side chains are important for the protein's structure and function, but it's the specific arrangement of these side chains that determines the protein's function, not just their types.
D) The tissue that produces the protein is not directly related to the protein's function.