BIOL 330 Study Guide - Final Guide: Hemoglobin, Thyroid Hormone Receptor, Cytosine
Document Summary
Extracellular matrix = a complex network of macromolecules (proteins, glycosaminoglycans, proteoglycans) secreted by cells. Occluding junctions: seal cells together into sheets (forming an impermeable barrier). Communicating junctions: allow exchange of chemical/electrical information between cells. Tight junction: each cell possesses integral membrane proteins that bind to similar proteins in the adjacent, forming a continuous weld. Types of extracellular matrix proteins include hyaluronan, aggrecan, collagen, and fibronectin. Cell to cell connections are mediated by cadherins, which are receptors that extend out from the cell, binding to other cadherins. A desmosome refers to the whole complex including cadherin proteins, filaments, cytoskeleton, etc; a desmosome forms when cadherins attach to intermediate filaments via anchoring proteins. Examples of proteins in the extracellular matrix include collagen, elastin, fibronectin, laminin. The elasticity of the components of the extracellular matrix is one of the key components. For example, elastin-molecules will crosslink to create a very elastic, gelatinous material.
