BIOL 200 Chapter 3: Topic 3.1 – Nuclear Structure & Protein Import (The Interphase Nucleus)

• School: UBC
• Department: Biology
• Course: BIOL 200
• Professor: Vivienne Lam

Document Summary

Phosphodiester bond: covalent chemical linkage in nucleic acids. Directionality (polarity) of a nucleic acid strand always read 3" to 5". New nucleotides are added to the 3" end during nucleic acid synthesis. Topic 3. 1 nuclear structure & protein import (the interphase nucleus) Damage to dna could result in the death of the cell. Therefore, the structure of the nucleus is designed to maximize its protective power (includes permeability of substances through nuclear pores). A double membrane (surrounds contents of nucleus) that consists of an inner and an outer membrane with perinuclear space in between. The nuclear envelope forms from er at telophase and breaks up with the er in late prophase of mitosis. Outer (cytoplasmic) surface of the envelope is studded with ribosomes like rer. The nuclear lamina (a meshwork of intermediate filaments) provide support to the nuclear envelope. Perinuclear space: also continuous with the er lumen.