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What is Blood group antigen NAG transferase present but galactosyltransferase is absent in and explain in detail?
A and B antigens are glycoproteins that differ in their terminal sugar.Under the influence of A or B genes, HAg is conveed into A or B antigen. Individuals with A gene express A transferase that catalyzes placement of a terminal N-acetylgalactosamine on H antigen to form A antigen.Those with B gene express B transferases that place a terminal galactose on the H antigen to form B antigen. Type AB individuals have both transferases.Ref: Textbook of medical physiology by N Geetha, 3rd edition, page no. 134