There are 880 G-nucleotides in the DNA molecule, which is 22% of the total number of nucleotides. Determine the number
There are 880 G-nucleotides in the DNA molecule, which is 22% of the total number of nucleotides. Determine the number of remaining nucleotides in this molecule and the length of this molecule?
1) Find the total number of nucleotides in the DNA molecule:
880 guanyl nucleotides corresponds to 22%,
x – 100%, x = 4000 nucleotides (A + T + G + C).
2) According to Chargaff’s rule (G = C) of cytidyl nucleotides in a molecule is 880, and the amount of adenyl and thymidyl nucleotides is calculated as follows:
4000 – (880 + 880) = 2240: 2 = 1120 nucleotides.
3) There are 4000 nucleotides in a molecule. One turn contains 10 pairs of nucleotides, its length is 3.4 nm, which means that the total number of turns is 4000: 20 = 200. Then the length of the molecule is 3.4 nm * 200 = 680 nm.