Defensive proteins are manufactured by the _ system.
The correct answer and explanation is:
Correct Answer: Immune system
Explanation (300 words):
Defensive proteins are manufactured by the immune system, which serves as the body’s primary defense mechanism against infections and diseases. These proteins play a critical role in identifying, neutralizing, and removing harmful pathogens such as bacteria, viruses, fungi, and parasites.
There are several key types of defensive proteins produced by the immune system:
- Antibodies (Immunoglobulins): These are Y-shaped proteins produced by B cells (a type of white blood cell) in response to the presence of antigens—foreign substances that trigger an immune response. Antibodies bind specifically to these antigens, marking them for destruction by other immune cells or neutralizing them directly.
- Complement Proteins: These proteins circulate in the blood in an inactive form and become activated during infections. Once activated, they enhance the ability of antibodies and phagocytic cells to clear microbes and damaged cells. They also promote inflammation and attack the pathogen’s cell membrane.
- Interferons: These are signaling proteins released by host cells in response to the presence of viruses. Interferons interfere with viral replication within host cells and activate other immune cells, like natural killer cells and macrophages.
- Cytokines: Although not exclusively defensive, these proteins serve as messengers between cells of the immune system. They regulate the intensity and duration of the immune response by stimulating or inhibiting the activity of various immune cells.
- Defensins and Lysozymes: These are small antimicrobial proteins and enzymes that directly destroy pathogens, often by disrupting their cell membranes.
Together, these defensive proteins help the immune system maintain the body’s internal environment, protect against disease, and ensure a rapid and efficient response to pathogens. Without these proteins, the body would be vulnerable to a wide range of infections and illnesses.