MCB 2050 Lecture 2: MCB 2050 V.2
Document Summary
Nucleus: primary difference between prokaryotes between prokaryotes and. Organized internal nuclear structure: prokaryotes possess a region (nucleoid) where the chromosome is located. Characteristics: irregular shape; typically one/cell, largest organelle. 2 main functions: compartmentalization of the cellular genome and its activities. E. g. site of dna replication, transcription & rna processing. E. g. cite where translation components (ribosomes, mrna, trna) are synthesized: coordination of cellular activities. E. g. control of metabolism, protein synthesis, reproduction (cell division), etc. Nuclear envelope: nuclear membrane, nuclear lamina, nuclear pores. Nuclear content: chromatin, nucleoplasm, nuclear matrix (maybe?, nucleolus. 2 parallel phospholipid bilayers: separated by 10-50 nm. Inter membrane 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, inner and outer membranes join at nuclear pores. Functions: separates nuclear content from cytoplasm.