An antigen triggers a response from the immune system and an antibody is produced. All antibodies are immunoglobulins, therefore, the correct answer is immunoglobulin. More specifically, an immunoglobulin is a protein produced by plasma cells to fight and neutralize pathogens. To do so, the immunoglobulin has a specific region which is complementary to a specific region of the antigen. Immunoglobulin's mechanism of action is to bind to the pathogen and either block its action or trigger a response of other cells of the immune system.
When boiling an enzyme, the chemical bonds that hold the enzyme together start to break down. this results in the enzyme to loss it's three-dimensional structure and casuses it to no longer fit their target substrate molecules, and the enzyme stops functioning.
