Question

Why do ddNTPs in Sanger sequencing serve as terminators of the polymerase reaction? O because they have an extra oxygen in Carbon 3 and no peptide bond can occur with the following nucleotide. O because they lack an oxygen in Carbon 3 and no phosphodiester bond can occur with the following nucleotide. O because they lack an oxygen in Carbon 5 and the polymerase detects that as a termination signal Because they lack a phosphate group in Carbon 5 and the polymerase detects that as a termination signal

Answer 1

Ans. Because they lack an oxygen in Carbon 3 and no phosphodiester bond can occur with the following nucleotide. DNA Named after the inventors Sanger and his colleagues the sequencing method is called Sanger sequencing where special type of terminator is used. The terminator that is used here have a special feature thus it is called dideoxynucleotide triphosphate. This dideoxy mucleotides has lack of an oxygen or the hydroxyl ion is not there in the 3rd Carbon, so.it does not able to form a phosphodiester bond with the next nucleotide. In deoxy nucleotide which generally has hydroxyl group in its 3' carbon can easily help in formation of phosphodiester bond, which allows DINA polymerase to synthesize the DNA but the missing hydroxyl in da NTP stop DNA polymerase thus terminate the sequencing. group