Assuming that the 30nm chromatin fiber contains about 20 nuc

Assuming that the 30-nm chromatin fiber contains about 20 nucleosomes (200 bp/nucleosome) per 50 nm of length, calculate the degree of compaction of DNA associated with this level of chromatin structure. What fraction of the 10,000-fold condensation that occurs at mitosis does this level of DNA packing represent? Full calculation please.

Solution

In 30nm fiber compaction DNA is compacted 27 fold relative to its extended length.

Amount of double stranded DNA in 50nm is ;

20nucleosomes ×200bp/nucleosome × 0.34nm/BP

=1360nm.

1360/50 = 27.2

Degree of compaction is 27.2