Major Groove Minor Groove A T G C T T T G G G G A A A C C C C 5' 3' 3' 5' 0.34 nm between nucleotides One helical turn= 3.4 nm 10 nucleotides DNA Structure 3' 3' 5' 5' Anti-parallel orientation A. The Concept DNA has a regular structure. It's orientation,...
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Major Groove Minor Groove A T G C T T T G G G G A A A C C C C 5' 3' 3' 5' 0.34 nm between nucleotides One helical turn= 3.4 nm 10 nucleotides DNA Structure 3' 3' 5' 5' Anti-parallel orientation A. The Concept DNA has a regular structure. It's orientation, width, width between nucleotides, length and number of nucleotides per helical turn is constant. All of these features were described by Watson and Crick. Adenine is always opposite thymine, and cytosine is always oppostie guanine. The two strands are held to- gether by hydrogen bonds: two bonds between adeninine and thymine and three bonds between guanine and cytosine. 2.0 nm Helix Nucleotides Helix Form Direction per turn Diameter A Right 11 2.3 nm B Right 10 2.0 nm Z Left 12 1.8 nm Figure 3. The structure of common DNA molecules. . . . . . . . . . . . . . . . . . . . . . . . This figure describes the general features of B DNA, the most common structure found within a cell. Other forms of DNA also exist. All forms have unique featur
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