Question

Biochemistry Lecture 6-Nucleic Acid Structure

Question: Define the terms "major groove" and "minor groove" with respect to the DNA double helix, and explain why the molecule has these characteristics. (Typed or neat handwriting pleasant thank you!)

Answer 1

2nm Ans 51 CS I major groove (224) minor groove / Magor - PT Minor groove (128) 9700 ve G DNA double helix mode - A DNA has a grooves (ie.) major and minor groove. - Grooves are not equal ui size and opposite to each other. - Each base pair rotate ui 36° around the axis. & lo base pours gofate ur 360° makes a complete turn. * Twisting of the a strando around one another forms double helix with minor groove with 12 Å and across and a major groove with 22 Å across e Angle at which the sugar pr base of fackbone of DNA profrude out from base pair iš 120° or 240°. Major groove = 240° minor groove

Why DNA forms groover :- Because the two glycosidic fonds are not diametrically opposite of each other, each base pair has a wider side that defines the major groove and a more narrow side that define the minor groove. ex! CH3 major groove ..MN - NA WV glycolichic . gly cou'dic - bond bond on Adenine base Thyminen ban Minor groove * The larger angle of major groove contains Following structure - A hydrogen bond acceptor (N7 of Adenine) - A H bond donor - A H bond acceptor - A hydrophobic surface (Methyl group of lig Thymine) * Minor groove has - H-boud acceptor - one t-atom