Question

1. What are the functionally distinct domains (regions) of antibody and TCR molecules?

2. What are the differences in the types of antigens recognized by antibodies and TCRs?

3. What mechanisms contribute to the diversity of antibody and TCR molecules?

Answer 1

Answer q 1

These two domains of antibodies and T cell receptors are cell mediated immunity. both are similar in structure but they recognize their antigen in dirrerent ways.Antibodies are also called immunoglobulin (Ig) are produced by plasma cells in the response to foregin bodies.Antibodies bind to a diverse set of antigenic shape. it is a y shaped protein produced by B cells . They are demonstrated by various type of reactions such as agglutination ,percipitation ,complement fixation ,neutralization,immobilization and inhibition.

TCR molecule

TCR molecules recognise linear peptides presented by a major histocompatibility complex.

T cell receptors are the lymphocytes called T cells , this mechanism of immunity is effective against intracellular pathogens (such as viruses or fungi ) malignent cell and graft of foregin tissues .T cell response result in cytotoxic which attack the altered cells and also it help in memory. It consist of two different type protein chain . they are alpha and beta chain. The antigen specificity of both receptors is determined by the sequence and structure of their complementarity determining region.

Answer q 2

Antigens are chemical markers that identify cells or molecules . human cell have their own antigens, thousands of markers that identify the cell as self. These are the major histocompatibility complex antigen also known as human leukocyte antigens. The T-cell receptors only bind to antigen which is presented on major histocompatibility complex protein.There are three type of antigen found by antibody they are Exogenous antigen , Endogenous antigen and auto antigens.

Answer q 3

Antibodies and TCR molecules responsible for immunity . they destroy the pathogens or other material and to prevent further cases of infectious disease. The both Tcells and B cells arise in the bone marrow ., the Tcells then migrate to the thymus where the thymic hormone bring about their maturation .from the thymus it goes to lymph nodes and spleen where as the B cells mature in the bone marrow and migrate directly to lymphatic tissue.These molecules where activated during an immune response ,T-cells perform direct attack ,B-cells differentiate in to plasma cells that release antibodies for an indirect approch .The T cell mediated immunity is effective agaist intracellular pathogens such as viruses or  fungi ,Malignant cells and graft of foregin tissue

The antibodies combined with their specific antigen and nullify their harmful effect.If the antigens are toxins they neutralise them.In the case of viruses they combined with them and prevent their entry in to the cells in which alone they can multiply.When the antibody combines with more than one antigen molecule,it cause them to clump and renders them more easily phagocytosable.