Human biochem lecture 11

Adaptive Immune System

A part of the immune system which adapts its response based on previous encounters with pathogens, primarily involving B cells and T cells.

Antigen

A substance that elicits an immune response, can be infectious particles or a variety of substances including the body's own cells.

B Cells

A type of white blood cell that produces antibodies and retains the memory of pathogens for a quicker response during future encounters.

T Cells

White blood cells that help in presenting antigens and eliminating them from the system; they assist B cells in their functions.

Antibodies

Globular proteins produced by plasma cells derived from B cells that recognize and bind to antigens.

Plasma Cells

Effector B cells that produce soluble antibodies in response to an antigen.

Memory Cells

B cells that retain information about antigens after the initial immune response, enabling a faster and stronger response upon re-exposure.

IgM

The largest immunoglobulin produced during the early response to an invading microorganism, consisting of five Y-shaped units.

IgG

The most abundant circulating antibody known as gamma globulin; it can cross the placenta to provide immunity to the fetus.

IgA

An immunoglobulin found in body secretions like saliva and tears; it protects mucosal areas from infection.

Opsonization

The process of marking an antigen for phagocytosis by coating it with antibodies.

Agglutination

The clumping of pathogens together by antibodies, preventing them from inducing target cells and making them easier to phagocytize.

Complement Activation

A function of antibodies that initiates the inflammatory response and leads to cell lysis.

Variable Region

Portion of an antibody that varies between different antibodies and is responsible for binding specific antigens.

Constant Region

The parts of an antibody that do not vary and are shared among different antibodies of the same class.

Hypervariable Loops

Regions in the antibodies' variable sections that interact with antigens and determine the specificity of an antibody.

Shape and Charge Complementarity

The phenomenon where Ig molecules match not only the shape of antigens but also their charges, facilitating strong binding.

Clonal Expansion

The rapid proliferation of specific B cells upon exposure to an antigen, resulting in increased antibody production.

Cytokines

Signaling molecules produced by T cells that activate B cells and enhance the immune response.