The Glycoprotein Page
Glycoproteins are the funny-looking appendages that stick out from the cell membrane (see main page picture). They're basically a membrane protein, only they have a chain of carbohydrates attached to them. Glycoproteins function as cell marker proteins in the membrane; they provide information as to what kind of cell it is. The aforementioned carbohydrates are attached by covalent bonding, where electrons are shared. The picture below is a really good one that is very detailed, but also a little confusing, so I'll attempt to explain it. The red twisty part that goes through the membrane is the protein itself, and the blue part attached to it labelled "aligosaccharide side chain" is the carbohydrate chain. The rest of the membrane is drawn in black, and a COOH group and polypeptide chain are attached to the glycoprotein inside the cell. The extracellular space is the stuff outside the cell, while cytosol is the stuff inside the cell.
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