Describe active versus passive immunity and provide an example of each. Define antibody or immunoglobulin and describe the five molecular classes of immunoglobulins and their function(s) in the body

Immunity can be categorized into two distinct types: active immunity and passive immunity. Active immunity occurs when the body develops its own protection against a certain pathogen by producing antibodies or white blood cells which recognize and destroy it upon reinfection. An example of this type of immune response is seen in individuals who have been vaccinated with attenuated strains of a virus. In this situation, the body will produce antigen-specific IgG antibodies that protect the individual from infection later on if they are ever exposed to wild-type versions of the virus.

Passive immunity, on the other hand, does not involve any kind of production by the person’s body but instead involves getting preformed antibodies either directly from another animal (e.g., via colostrum) or through injection (e.g., tetanus shot). This type of immunity confers protection against only one specific pathogen and typically only lasts for a few weeks or months; therefore, it cannot provide long lasting resistance like active immunity can. An example of this would be giving an infant human immunoglobulins at birth as part of their immune system development while they wait to build up their own natural defense mechanisms postnatal antibody maturation process but this won’t provide much protection beyond those first few months following birth due to its transient nature.

An antibody (also known as an immunoglobulin) is a protein created by B cells (a type of white blood cell) in response to an antigen exposure and binds specifically to that antigen so that it can be recognized and destroyed more easily by other components within our immune system such as macrophages and neutrophils. Immunoglobulins are divided into five major classes based on structure: IgA, IgD, IgE ,IgG and IgM . All five classes contain heavy chains composed from four different domains which determine each class’s various roles within our bodies depending on their combinations/arrangement between one another :
1) IgA – found mainly in secretions such as saliva tears etc… Plays important role in mucosal defence egs increase levels seen with parasitic infections 2) IgD – found primarily on surface B lymphocytes helps initiate adaptive immune responses 3) IgE – plays major role in allergic reactions 4) IgG -major component found in circulation protects form bacterial infections 5 ) IgM – largest class produced during early stages after primary exposure to antigen acts as bridge between innate & adaptive immune systems

For example, if someone has a parasitic infection then we would expect an increase in levels of Immunoglobulin E(lge). As parasites usually enter through mucosa surfaces such as skin lumen for instance after coming into contact with these areas there would be increased activation local resident mast cells leading to degranulation which results releasing substances including histamines cytokines & chemokines also resulting increased concentrations IL4 secretion inducing differentiation B plasma cell optimized for synthesising high amount lge These newly generated lge bind parasite antigens neutralizing them further helping clear out infection .