Final answer:
The two classes of immunoglobulin light chains are kappa (κ) and lambda (λ). These light chains combine with heavy chains to form different classes of antibodies, such as IgG, IgM, IgA, IgD, and IgE, each having varying roles in the immune response.
Step-by-step explanation:
Immunoglobulins, commonly known as antibodies, are critical components of the immune system that interact with antigens to fight infections. The basic structure of an antibody consists of two heavy chains and two light chains bonded together. The light chains come in two classes: kappa (k) and lambda (λ). Each immunoglobulin has either both light chains of the kappa type or both of the lambda type, but not a mixture of both. In humans, approximately 65% of light chains are kappa, while the remaining 35% are lambda. The kappa light chain is composed of 214 amino acids with some sequence variability that contributes to the diversity necessary for the immune system to recognize a multitude of antigens.
The heavy chains determine the class or isotype of the antibody- IgG, IgM, IgA, IgD, or IgE. Each of these classes has different roles in the immune response, and they can vary in their abundance in the serum, size, arrangement, and functional roles. Despite differences in heavy chain classes, any type of heavy chain can pair with either kappa or lambda light chains to form a complete antibody molecule. However, the consistency remains such that within an individual antibody molecule, the two light chains are of the same type.