Question

After protein translation is complete, the newly-formed polypeptide A. embeds itself on the surface of a ribosome, which carries it back to the nucleus for alterations. B. folds into a three-dimensional structure due to the interaction of neighboring amino acids in sequence. C. moves to the mitochondrion, where it is broken down to form ATP. D. breaks down the RNA molecules that helped form the polypeptide.

Answer 1

B. folds into a three-dimensional structure due to the interaction of neighboring amino acids in sequence

Answer 2

B. folds into a three-dimensional structure due to the interaction of neighboring amino acids in sequence.

Step-by-step explanation:

After completion of translation the nascent polypeptide molecule enters endoplasmic reticulum (ER) from cytosol in order to fold into a specific three dimensional structure. A polypeptide becomes functional only after being folded, in nascent form it is non functional. In ER, a linear polypeptide molecule folds to form either an alpha helix or a beta sheet due to hydrogen bonding between various amino acids, these are secondary structures. These secondary structures then fold even more to form tertiary structure with the help of ionic bonds, hydrophobic interactions and disulphide linkage/bonds between various amino acids. After tertiary structure, finally a quaternary structure is obtained because of oligomerisation of two or more tertiary proteins. This well folded and oligomerised protein is usually a functional form of protein.