文档介绍：Chapter 6
Cytoplasmic matrix, Endomembrane system, Protein Sorting and membrane trafficking
Learning objective
1. Compartmentalization in Eukaryotic Cells;
The structural and functional relationship among the ER, plexes, lysosomes and plasma membranes of eukaryotic cells;
The pathways of proteins targeting and sorting, and its mechanisms;
The ways of protein modifications and intracellular sites after they are synthesized;
Types of vesicle transport and their functions.
1. partmentalization in Eukaryotic Cells
Membranes divide the cytoplasm of eukaryotic cells into partments.
Three categories in eukaryotic cells:
(1) the endomembrane system: ER, plex, Lys.,
secretory vesicles.
(2) the cytosol.
(3) mitochondria, chloroplasts, peroxisomes, and the nucleus.
Membrane-bound structures (organelles) are found in all eukaryotic cells.
Cytoplasmic matrix and its functions
Cytoplasmic Matrix: The region of fluid content of the cytoplasm outside of the anelles. Aqueous solution of large and small molecules including filaments of cytoskeleton which act anizer for some order.
The Cytosol is the site of protein synthesis and degradation or modification. It also performs most of the cell’s intermediary metabolism.
Cytoplasmic matrix (Cytosol) and
Endomembrane System
Functions of cytoplasmic matrix:
The protein synthesis, degradation and modification.
Cells carefully monitor the amount of misfolded proteins. An accumulation of misfolded proteins in the cytosol triggers a heat-shock response, which stimulates the transcription of genes encoding cytosolic chaperones that help to refold the proteins.
B. Endomembrane System
Endomembrane System : The structural and functional anelles including ER,plex, lysosome, endosomes, secretory vesicles.
Membrane-bound structures (organelles) are found in all eukaryotic cells.
partment % of total cell volume
Cytosol 54
Mittchondria 22
Rough ER cisternae 9
Smooth ER cisternae plus Golgi cisternae 6
Nucleus 6
Peroxisome 1
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