What is the Difference Between Antigen and Pathogen?

The main difference between an antigen and a pathogen lies in their roles in the immune system and the infection process:

• Antigen: An antigen is a substance that triggers the production of antibodies in the body. It is a component of a pathogen, such as a cell surface marker comprised of proteins and complex carbohydrates, that is identified by macrophages of the innate immune response as "foreign" to the body. Antigens stimulate the immune system to produce antibodies, which are Y-shaped proteins that help fight off the infection.
• Pathogen: A pathogen is a microbe that can cause illness or disease in its host. Pathogens include bacteria, viruses, protozoa, and fungi. Each pathogen has a unique antigen that binds to special receptors in the host's body, which the immune system recognizes as a threat, leading to the production of antibodies in response.

In summary:

• Antigens are substances that trigger the production of antibodies in response to a pathogen.
• Pathogens are microorganisms that can cause diseases in their host, with each pathogen having a unique antigen.

Comparative Table: Antigen vs Pathogen

Here is a table highlighting the differences between antigens and pathogens:

Antigens are substances that trigger the production of antibodies, while pathogens are harmful microorganisms that can cause diseases in their host. Each pathogen has a unique antigen that binds to special receptors in the host's body, which is recognized as a threat by the immune system, resulting in the production of antibodies in response.