MCB 2050 Final: Cell bio - final.doc

• School: University of Guelph
• Department: Molecular and Cellular Biology
• Course: MCB 2050
• Professor: c

Document Summary

Nuclear envelope: nuclear membrane, nuclear pores, nuclear lamina. Nuclear contents: chromatin, nucleoplasm, nucleolus, nuclear matrix. 2 parallel phospholipid bilayers separated by 10-50 nm. Outer membrane binds ribosomes and is continuous with rough endoplasmic reticulum. Inner membrane bears integral proteins, which connect to nuclear lamina. Separates nuclear content from cytoplasm, separating transcription and translation. Selective barrier, allowing limited movement of molecules between nucleus and cytoplasm. Thin meshwork: lamins (type 5 if) is approximately 10nm is diameter and it integrity is regulated by phosphorylation. Bound of the inner surface of the ne via prenyl group at c-terminal cysteine and lamin polypeptide. Membranes fuse to form pores approximately 120nm in diameter. Pores contain a complex protein structure called the nuclear pore complex (npc) About 200 polypeptides called nucleoporins (nup"s: ~25-30 different nup"s in multiple copies. An 8 fold repeat forming the structure called octagonal symmetry. Doughnut like cytoplasmic view; basket like nuclear view.