Biochemistry 2280A Chapter 7: Chapter 7

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Chris Brandl

Document Summary

You don"t want to degrade the gene permanently but sometimes you"ld like to turn it off: rna provides additional opportunities for regulation of gene expression (rna processing, rna export from the nucleus, etc. ) The first in a biological process is often highly regulated as it saves energy! The chemical linkage between nucleotides in rna a phosphodiester bond is the same as that in dna. Dna always occurs in cells as a double-stranded helix, rna is single-stranded. Because an rna chain is single- stranded, it can fold up into a variety of shapes, just as a polypeptide chain folds up to form the final shape of a protein; double- stranded dna cannot fold in this fashion. The ability of rna to fold into a complex 3d shape allows it to have structural, regulatory or catalytic roles. Rna molecules can form intramolecular base pairs and fold into specific structures.