LQB186 Lecture Notes - Lecture 12: Lipid Bilayer, Hydrophile, Cell Membrane
9 Aug 2018
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Document Summary
The extracellular matrix (ecm) is a mesh of protein fibres and glycoproteins that exist externally of the cell in multicellular organisms. The extracellular matrix provides structural and biochemical support to surrounding cells. Providing sites for anchorage by cells within a tissue and segregating separate tissues from one another. Sequestering and storing growth factors until receipt of a chemical signal. In plant cells the extracellular matrix includes cell wall components (like cellulose) plays an important role in: Providing mechanical strength and rigidity to the cell (maintains cell shape) Signalling over long distances: required to co-ordinate behaviour of cells in remote parts large complex multicellular organisms. Neurons specialised cells for intercellular communication over large distances. Fast and precise, high concentrations of neurotransmitters, low affinity for receptors, inactivated quickly. Endocrine cells secrete hormones into the bloodstream. Slow and general, hormone can act at very low concentrations. Contact dependent the cells are close enough together to allow direct interaction of the signalling proteins.
