A Feature Common to Most Transmembrane Proteins Is A(n)
A) $\alpha$

A feature common to most transmembrane proteins is a(n)

A) phosphorylated exterior domain.
B) $\alpha$ -helical region of about 20 to 25 hydrophobic amino acids.
C) amino acid sequence rich in acidic residues.
D) structure consisting almost exclusively of $\beta$ -sheets.