Glossary of Biochemistry & Molecular Biology
Subject:
Biology [1]
Tags:
Biology [2]
biochemistry [3]
Glossary of Biochemistry and Molecular Biology 3' end/5' end: A nucleic acid strand is inherently directional, and the "5 prime end" has a free hydroxyl (or phosphate) on a 5' carbon and the "3 prime end" has a free hydroxyl (or phosphate) on a 3' carbon (carbon atoms in the sugar ring are numbered from 1' to 5'. That's simple enough for an RNA strand or for single- stranded (ss) DNA. However, for double-stranded (ds) DNA it's not so obvious - each strand has a 5' end and a 3' end, and the 5' end of one strand is paired with the 3' end of the other strand (it is "antiparallel"). One would talk about the 5' end of ds DNA only if there was some reason to emphasize one strand over the other - for