I.Shown below is a space-filling model of the potassium ion channel, with amino acid side chains colored based on polarity. We are looking at the surface of the entire potassium ion channel.
A.What are the general types of amino acid side chains found on the outer surface of the potassium ion channel structure?
B.You know from question Itzt that the potassium ion channel is embedded in the cell membrane. Based on that fact, why is the distribution of amino acid side chains like it is?
C.Why are there more polar side chains concentrated on the top and bottom of the outer surfaces of the pore?
2. Shown below is a ribbon diagram of the potassium ion channel. Based on Chapter 4, what is the major type of secondary protein structure that the potassium ion channel has?
3.Now, instead of looking at the potassium ion channel from the perspective of how it sits in the membrane, let's look at it from the top (below left) and at one subunit from the side (below right). The potassium ion channel is made up of four identical subunits (a homotetramer).
a) How many alpha helices make up each protein subunit?
b) How many total alpha helices make up the potassium ion channel?