Two Polypeptide Chains Have the Same Amino Acid Composition and Molecular

Multiple Choice

Two polypeptide chains have the same amino acid composition and molecular weight, yet only one binds to a cell membrane receptor.Several possible scenarios have been listed to explain these observations.Which is the only plausible one?

A) One chain is longer than the other chain, causing the polypeptides to fold into different shapes.
B) One chain was synthesized in a laboratory, while the other was synthesized in a bacterium, causing differences in the final structures of the proteins.
C) One chain has bond linkages connecting amino acids that differ from the bond linkages in the other chain.
D) The two chains fold into different three-dimensional shapes because the polypeptides were made by two different organisms.
E) The two chains fold into different three-dimensional shapes because the sequences of amino acids differ in the chains.