BIOLOGY 2C03 Lecture Notes - Lecture 6: Histone H4, Histone H3, Globular Protein
Document Summary
Dna associated with proteins to form chromatin or chromosomes. Extent of compaction changes during cell cycle and when genes are being transcribed into rna. Interphase - dna in nucleus is unwound and open, still organized in distinct regions - proteins have chemical modifications to hold specific parts together for organization. Base pairs interact through chemical modifications that allow them to be connected - can be disrupted on a dna or protein level. 5 major types of histones: h1 h2a, h2b, h3, and h4. Spacing of histones first discovered in em image. Image was produced by adding just enough nuclease enzyme to cleave dna between them so they would be left with only dna wound around histones. Centromere, euchromatin (less dense), telomeres and other heterochromatin (more tightly packed chromatin) 4d nucleome = 3d genome mapping effort, revealed 10,000 loops. Lagging strand, leading strand, dna polymerase, replication bubble, replication fork (review)