As a result, per capita income in Northwest Arkansas has converged with the national average. As of 2012, income per capita in Northwest Arkansas was about $36,000, about $6,000 below the national average. After adjusting for the lower cost of living in the region, per capita income in Northwest Arkansas was at that time, in effect, $40,000, just $2,000 shy of the national average.
Protein channels are important to facilitate the transport of ions and other larger molecules across the plasma membrane.   Large molecules cannot just diffuse thorough the â¦ membrane. In addition, polar molecules cannot diffuse through the membrane since it would be energetically unfavorable for them to negotiate the hydrophobic interior of the plasma membrane. Therefore, protein channels are essential in membrane transport.
Membrane Proteins, page 2. In addition to the lipid bilayer, the cell membrane also contains a number of proteins. We have already mentioned the presence of certain proteins in the cell membrane. In this section we will discuss the different classes of proteins found there.hile the lipid bilayer provides the structure for the cell membrane, membrane proteins allow for many of the interactions that occur between cells. As we discussed in the previous section, membrane proteins are free to move within the lipid bilayer as a result of its fluidity.