What is "immunoglobulin"?

Immunoglobulin refers to a class of proteins that play a crucial role in the immune system, specifically functioning as antibodies. When the body detects foreign substances, known as antigens, immunoglobulins are produced by B cells in response to these threats. They bind to the antigens, helping to neutralize or mark them for destruction by other immune cells.

This process is essential for the adaptive immune response, allowing the body to recognize and remember pathogens for quicker responses in the future. Immunoglobulins come in various classes, such as IgG, IgA, IgM, IgE, and IgD, each with distinct roles in immune defense.

In contrast, the other options presented do not accurately describe immunoglobulin. The first choice defines a pathogen, which is a microorganism that can cause disease. The second choice refers to hormones, which are chemical messengers in the body that regulate various physiological processes, including metabolism, but are not directly related to the immune response. The fourth choice mentions a protein that enhances immune response, which could pertain to various components of the immune system but does not specifically address the function of immunoglobulins as antibodies.