BIOL 401 Lecture Notes - Lecture 2: Histone H1, G2 Phase, Sister Chromatids
16 Feb 2017
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Chromosomes consist of a longer (q) and shorter (p) arm. G1: cellular contents (excluding chromosomes) are duplicated. G2 phase: cell checks duplicated material from s phase for mutations and defects. **he"s teaching it as s g2 mitosis g1 . Size of dna and chromosomes: chromosomes must be very small to fit into the nucleus, so it undergoes a process to obtain the proper size. Dna is tethered to h1: histone proteins are very small positively charged proteins, which allows negatively charged dna to interact with it easily. Prophase: nucleosomes are furthered condensed into a solenoid: solenoid: 6 nucleosomes wrapped around one another, h1 is in the middle and nucleosomes are around it. Forms a 30nm fiber: scaffold: non-histone protein structure where solenoids are tethered. Consists of multiple proteins in a linear scaffold: scaffold attachment regions (sar): physically interact with scaffold, scaffolds form an alpha helix. Topoisomerase: enzymes that cut the dna and wrap itself around the amino acid string.
