blood antigens

What determines blood groups?

Blood types are determined by the antigens A and B found on the surface of red blood cells.

What antigens are present in blood type A?

Individuals with blood type A have antigen A on the surface of their red blood cells.

What antigens are present in blood type B?

Individuals with blood type B have antigen B on the surface of their red blood cells.

What antigens are present in blood type AB?

Individuals with blood type AB have both antigens A and B on the surface of their red blood cells.

What antigens are present in blood type O?

Individuals with blood type O do not have any antigens on the surface of their red blood cells.

What is the chemical composition of antigen A?

Antigen A is made up of N-acetyl-galactosamine (sugar) and substance H (protein).

What is the chemical composition of antigen B?

Antigen B is made up of galactose (sugar) and substance H (protein).

Where does the formation of blood antigens take place?

The formation of antigens occurs in the erythroblasts in the bone marrow.

How does allele A code for antigen A?

Allele A codes for transferase enzyme A, which adds N-acetyl-galactosamine to substance H to form Antigen A.

How does allele B code for antigen B?

Allele B codes for transferase enzyme B, which adds galactose to substance H to form Antigen B.

How does allele O lead to type O blood?

Allele O is a mutated allele that codes for an inactive enzyme, resulting in no sugar being attached to substance H.

How do mutations in genes affect blood type O formation?

Mutations by deletion lead to an inactive enzyme that cannot attach sugar to substance H, resulting in blood type O.

What causes alleles A and B to be formed?

Alleles A and B are formed due to 4 substitution mutations at the same nucleotide of the same codon.