DGS 3223 Lecture Notes - Lecture 1: Histone H2B, Histone H2A, Metaphase
8 Sep 2016
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Avery welch dgs 3223 lab in cytogenetics week 1 module 1 notes 9/4/15. Chromosomes are made up of long strands of dna. Mitotic pre-dna synthesis chromosomes have one dna molecule: chromatin must be packaged so the dna molecule can direct cellular function, under low salt, electron micrographs of chromatin appear to resemble 10 nm wide beads on a string. The beads are the nucleosomes, octamers of histone proteins, 2 each of. Nucleosomes coil into 30nm solenoid structure, stabilized by h1. The solenoid loops around a cellular protein scaffolding. Chromosome binds to scaffold proteins at regions called scaffold attachment regions. Centromere structure where the mitotic spindle attaches prior to segregation during anaphase; essential for the normal movement and segregation of chromosomes during mitosis. Chromosomes have a short arm (p) and a long arm (q) separated by a primary constriction called the centromere: metacentric chromosomes short and long arms of roughly equal length with the centromere in the middle.
