DNA wraps around histone proteins to form nucleosomes that coil into compact chromatin.
About 147 base pairs wrap around a histone octamer (two each of H2A, H2B, H3 and H4) to make a nucleosome, like beads on a string. H1 helps fold the fibre into a 30 nm fibre and loops. Heterochromatin is tightly packed and silent; euchromatin is open and active.
Two metres of DNA fit into a nucleus about 6 micrometres wide.
DNA wraps around histone proteins to form nucleosomes that coil into compact chromatin.
DNA Packaging is one of the 52 topics in Molecular Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Chromatin Remodelling, Gene Expression, Histone Modification.
Chromosomes are most condensed in metaphase.
DNA Packaging is a Beginner topic, so no earlier topic is required. Other Beginner topics in Molecular Biology that pair well with it include Central Dogma, DNA Replication, Base Pairing.
The closest topics to DNA Packaging are Chromatin Remodelling, Gene Expression, Histone Modification, Translation. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for DNA Packaging. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
DNA Packaging: DNA wraps around histone proteins to form nucleosomes that coil into compact chromatin. Chromatin Remodelling: ATP-dependent complexes slide or evict nucleosomes to control access to DNA. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Chromatin Remodelling and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
ATP-dependent complexes slide or evict nucleosomes to control access to DNA.
🧫 Molecular BiologyThe process by which information in a gene is used to make a functional product.
🧫 Molecular BiologyAcetylation, methylation and phosphorylation of histone tails alter chromatin openness and gene activity.
🧫 Molecular BiologyRibosomes read the mRNA codons to assemble amino acids into a protein.
🧫 Molecular Biology