Blood is essentially an aqueous solution but it must transport a variety of non polar substances (hormones for example). Colloidal proteins, termed albumins, facillitate this transport. Must these albumins be polar or nonpolar?
Since plasma is made up primarily of water, it is essentially a polar medium. Nonpolar compounds, such as many hormones and fatty acids, need to be transported in plasma by binding to albumins and other plasma proteins. Therefore, such proteins must have hydrophobic or nonpolar binding regions ...