Biology And Biomedical Sciences BIOL 2960 Lecture Notes - Lecture 3: Endoplasmic Reticulum, Nuclear Lamina, Nuclear Membrane
19 Feb 2016
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Document Summary
Electron micrograph reveals details: nuclear envelope has 2 layers, contiguous with endoplasmic reticulum. Nucleolus: site of ribosomal biogenesis and assembly, nucleoplasm region outside of the nucleolus. Inside nucleus: dna replication, mrna synthesis (transcription) Outside nucleus: protein synthesis (translation, many molecules move back and forth, via pores, not an open hole, highly regulated. Protein synthesis takes places here, for proteins to be exported, or put. Synthesis or proteins that need to be kept away from cytoplasm into membrane (digestive enzymes) Various modification of proteins take place in rer. Ribosomes bound to rer are not a stable part of rer: constantly being bound and released from membrane, ribosomes bind to rer when it is translating a protein that is destined for secretion contains signal peptide. Membranes of the nucleus, er, the golgi apparatus, and lysosomes form a network. Golgi apparatus: vesicles carried by motor proteins, along cytoskeletal tracks, microtubules, actin filaments. Composed of flattened sacs of membrane (cisternae) and small vesicles.
