Ribosomes are the rna-protein enzyme complexes that synthesize proteins. there are no ribosomes inside the lumen of the secretory pathway. instead, secreted and membrane-bound proteins are synthesized in the cytosol, but have short stretches of amino acids called "signal sequences" that target the newly-forming proteins to a special channel in the membrane of the er that enables the movement of the newly-forming proteins into the er. this "translocation" ceases if a protein sequence is reached that will be embedded in the plasma membrane. protein synthesis will proceed, and the membrane-spanning sequence will eventually be embedded in the er membrane. which of the following features would such a transmembrane amino acid sequence have?
a. the amino acids would have mostly hydrophobic side-chains.
b. the amino acids would have mostly hydrophilic side-chains.
c. there's no way to predict the relative number of hydrophobic and hydrophilic side-chains in transmembrane amino acid sequences.