And so these calcium ions can basically locate the negatively charged side chain groups of proteins, or they can even bind to the oxygen of the carbonyl groups found on the backbone of the protein. And that can form strong interactions. And once those interactions form, the calcium can induce conformational changes in the structure of the protein, and that can bring the different domains in the protein together. It can basically expose important hydrophobic regions of the protein, and that can allow that protein to interact with other proteins, and that can stimulate many different types of reactions in the cell. So, again, due to the positive charge, due to a positive charge of two, calcium odds can form strong interactions with the negatively charged side chain groups of proteins, as well as the oxygen atoms on the carbonyl groups of the protein backbone. As a result of this, when calcium bonds to proteins, it can cause conformational changes in the structure of the protein, that can link different domains in the protein.