Proteins, which are composed of amino acids, help transport lipids in the bloodstream. These proteins need to be able to cluster with other nonpolar molecules and exclude water. Which of the following would best describe the side chains of these amino acids in the lipid transport proteins?
A.
A more positive hydropathic index
B.
A more negative hydropathic index
C.
A neutral hydropathic index
D.
A pKa of the primary carboxylic acid group of approximately 2
E.
A pKa of the α -amino group of approximately 9.5