MCB 2050 Lecture Notes - Lecture 13: Nuclear Pore, Enclave And Exclave, Endomembrane System
Document Summary
Nuclear envelope boundary between cytosol and nucleus. Nuclear pores doorways" in the nuclear envelope. ** prokaryotes possess a region" (nucleoid) where the chromosome is located: poorly separated region of the cells that lacks a boundary membrane to separate it from the surrounding cytoplasm. Irregular shape; typically, one/cell: largest organelle (5-10% of cell volume) Two main functions: compartmentalization of the cellular genome and its activates, site of dna replication, transcription and rna processing, site where translation components (ribosomes, mrna, trna) are synthesized, coordination of cellular activities, control of metabolism, protein synthesis, reproduction. Nuclear envelope: nuclear membrane, nuclear lamina, nuclear pores. Nuclear content: chromatin, nucleoplasm, nuclear matrix, nucleolus. 2 parallel phospholipid bilayers: separated by 10-50 nm. Intermembrane space: outer membrane binds ribosomes and is continuous with rer. Inner membrane: contains unique protein composition distinct from outer membrane. Integral membrane proteins that connect to nuclear lamina. Intermembrane space (nuclear envelope lumen) is continuous with er lumen.