LECTURE 2 - TOPIC 2 CELL MEMBRANES
Presence of cell membrane, is one of key innovations to eukaryotic cells.
(Read text for better description of cell-cell signalling)
Slide 2- function of cello membranes (overview)
Fluid mosaic mode (1972)l- provided unified model.
-Membrane consisted of A fluid layer (bi-layer) in to which is studded a unique complement of proteins.
-Lipid bi-layer is structural basis of membrane, and forms selectively permeable layer.
-Proteins are also freely floating within cell (mosaic of proteins)
-Membrane define boundaries of cell, and within cell, and form the selectively permeable layer.
-Membranes usefull as organization (enzymes linked to membranes for biochemical activities, like in the
ETC --> to give affective ATP synthesis)
-membranes also useful for controlling the movement of solutes in and out of the membrane (Na+ K+
-membrane is the first point of contact between the cell and its environment
-Allowing it to respond to its environment, and create a cellular response "signal" (cell to cell
-In multi-cellular organism, cells need to be able to link to each other and share materials within one another.
-Communicating junctions, where cells can share things within each other.
Mitochondria are highly lined in proteins, are not so many lipids
but in shwan cells the are almost all lipid, and lightly in protein.
Details of membrane structure can be tailored
Fluid mosaic model:
-double layer of lipids
-held together by non-covalent interactions
-Lipid bilayer forms structural basis of membrane (& permeability layer)
-studded into this by-layer is the unique complement of proteins responsible for specific function of
-packed into 10nm
Emphasis on fluid nature of membrane.
took 2 cells mouse & human, and gave them two different coloured labels on membranes. then they fused
them together. If membra