Due to the chemical composition of the pentose residues of the bases, DNA strands have directionality. One end of a DNA polymer contains an exposed hydroxyl group on the deoxyribose; this is known as the 3' end of the molecule. The other end contains an exposed phosphate group; this is the 5' end. The two strands of a double-helix run in opposite directions. Nucleic acid synthesis, including DNA replication and transcription occurs in the 5'→3' direction, because new nucleotides are added via a dehydration reaction that uses the exposed 3' hydroxyl as a nucleophile.:27.2
Due to the chemical composition of the pentose residues of the bases , DNA strands have directionality . One end of a DNA polymer contains an exposed hydroxyl group on the deoxyribose ; this is known as the 3 ' end of the molecule . The other end contains an exposed phosphate group ; this is the 5 ' end . The two strands of a double - helix run in opposite directions . Nucleic acid synthesis , including DNA replication and transcription occurs in the 5'→3 ' direction , because new nucleotides are added via a dehydration reaction that uses the exposed 3 ' hydroxyl as a nucleophile.:27.2
What causes the directionality of DNA strands?
What causes the directionality of DNA strands ?
the chemical composition of the pentose residues of the bases
the chemical composition of the pentose residues of the bases