Question

The antibodies are
(A) Proteins
(B) Carbohydrates
(C) Lipids
(D) Germs

Answer 1

Hint: Antibodies are produced in our own body, that is they are not foreign particles. They are one of the key bodies used by our immune system against antigens. Antigens are proteinaceous in nature and are present on pathogens.

Complete Step by Step Solution:
Antibodies are produced by B cells; these are specialised white blood cells. Whenever any foreign particle (antigen to be specific) comes in contact with B cells of blood also known as plasma cells, these plasma cells clone and multiply and produce millions of antibodies and release these antibodies in our blood and lymphatic system. Antibodies are also known as immunoglobulins or Ig, it is a Y shaped large structure which is specific for antigen.

A healthy immune system produces antibodies in an effort to protect us, antibodies are basically produced when they react with infectious organisms, toxins and pollen. Antibodies have a specific antigen binding site known as epitope and this is formed by the amino terminal ends of light and heavy chains. Similarly, antigens have antibody binding sites known as paratopes. Antibodies are made up of two light and two heavy chains joined by disulphide bonds so it is also known as L₂H₂.

Different types of antibodies are IgG, IgM, IgA, IgD, and IgE. These are differentiated on the type of heavy chain found in the molecule. IgM is the largest antibody and it is the first antibody to appear in response to initial exposure to antigen. IgA performs immune functions of mucous membranes, also present in abundant quantities in colostrum. IgD helps to activate B cells in activation. IgG is the main type of antibody found in blood to control infections in our body, this antibody is small in size so can cross the placenta and reach upto foetus. IgE functions against allergic infections.
Antibodies are soluble glycoproteins.
So, option (A) is correct.

Note: Note that all the five antibodies have the same nature, they function or work on different areas on the basis of their size and the variable region in their structure that is their epitopes. But chemically all the five antibodies are soluble proteins.