Blood is the liquid connective tissue in our body. Blood is made up of two major components, the acellular fluid part called plasma and the cellular components of blood. The plasma of blood is made up of water and a number of protiens. One of such protiens is called antibody. The cellular components of blood contains the red blood cells, the white blood cells and platelets. The RBC have a specific protein that they express on their surface called surface proteins. It’s this surface antigen and antibody that determine the blood group. Your body has all the antibodies which are not complimentary to the surface antigen.
Your blood group is determined by your genetic makeup. There are 3 possible alleles for the gebe
According to the ABO classification there are 4 types of blood group found in humans.
The surface antigen on RBC of this group is composed of a non branched glycoprotein. The fucose ring on the surface is is connected to a galactose. The galactose moeity is joined to a N-acetylglucosamine , which in turn is linked to a galactose ring.
The plasma of these individuals have both the anti A and anti B antibodies. That is to say the antibodies in this kind of people have antigens which can recognise and react against bit A and B antigens.
The surface antigen is formed of a branded glycoprotein. The basic linear structure of the antigen is kept intact here , the only difference is that the galactose ring in between the fucose and the N-acetylglucosamine is also connected to a N-acetylgalactosamine.
The plasma of these individuals have antibodies sensitive to B antigens only. The antigen and recognise and react when they come in contact with A antigens.
The surface antigens of this kind of blood cells are also branched glycoproteins. The linear structure of O antigens are present but the galactose ring between the fucose and N-acetylglucosamine is joined to a galactose ring.
The plasma of these individuals have antibodies capable of recognising and reacting against A antigens.
Thus type of blood cells expres both A and B types of surface antigens. They are both branched glycoproteins.
The plasma of such blood lacks all kinds of antibodies. Thus on addition of A or B they can react.
5) Bombay type:
This the rarest of all types of blood groups discussed so far. Essentially the H antigen is present in all types of blood groups initially. Later due to genetic events they get modified to produce either A or B or O kind of antigens. However in special cases no such events take place and the H antigen remains unmodified. The people with Bombay type of blood groups have in the H antigen on their RBC. The H antigen is formed of just an N-acetylglucosamine group in between of two galactose units.
The blood plasma surprisingly has three kinds of antibodies: antiA, antiB and antiO.
Rh factor classification:
Rh factor is a antigen present in humans which also plays an important role in determining the blood group. The important player of this part is the D antigen. The presence or absence of D antigen determines whether the person is Rh+ve or Rh-ve. This blood grouping is combined with the ABO grouping to get a comprehensive idea about the blood group.
The types of blood groups under this classification are:
1)A-ve: Has A antigen but lacks D antigen.
2)A+ve: Has both A as well as D antigen.
3)B+ve: Has antigen B along with antigen D.
4)B-ve : Has antigen B but there is no antigen D present.
5)O+ve: Has O antigen with D antigen.
6)O-ve: Has O antigen without D antigen.