Now, both types of proteins, integral as well as peripheral, can have sugar or carbohydrate components which protrude outside the cell. Remember, sugars are polar, and our cytosol, as well as the extracellular fluid is, in fact, polar. So these sugar components will basically attach themselves to our integral proteins or peripheral proteins and will point directly outward, as shown. And the sugar protein combinations are known as glycoproteins. Glycoproteins are important because these sugar components can basically allow some outside type of molecule to bind onto our sugar component of that protein. And we'll talk more about this when we get into biochemistry of cell membranes.