A genetic forensic researcher miraculously perfectly isolates an ultra-short fragment of a DNA doubl — Biomolecules Chemistry Question
Question
A genetic forensic researcher miraculously perfectly isolates an ultra-short fragment of a DNA double helix containing exactly $5$ complete helical turns end-to-end. According strictly to the standard precise Watson and Crick helical model formally described in your literature, exactly how many base pairs are contained perfectly in this DNA segment, and what is its approximate axial structural length?
💡 Solution & Explanation
The rigid structural Watson and Crick double-helix model strictly defines exactly 10 complementary base pairs integrated perfectly per every single complete helical turn. Furthermore, exactly one complete helical pitch (turn) corresponds geometrically to $3.4\text{ nm}$ ($34\text{ \AA}$). Thus, precisely $5$ full turns contain exactly $50$ base pairs and perfectly span $17.0\text{ nm}$ ($5 \times 3.4\text{ nm}$).