Protein immunity is best described as

• A. Antibodies that protect body
• B. Enzymes that regulate the rate of chemical reactions
• C. Proteins that store energy
• D. Carbohydrates that provide structure

Answer: (A)

Protein immunity centers on antibodies, the immune proteins produced by B cells that recognize and defend against specific invaders. Each antibody has a unique binding site that fits a particular antigen on a pathogen, allowing neutralization or marking the pathogen for attack by other parts of the immune system. This targeted, adaptive response is what antibodies do best. Enzymes are proteins too, but their job is to speed up chemical reactions rather than provide targeted defense. Proteins can have storage roles, and carbohydrates can provide structural support, but those functions aren’t what antibody-mediated immunity is about. So antibodies protecting the body best describes protein immunity.