試題詳解

42. Misfolded proteins in the cell are commonly sent to the proteasome for degradation. Which of the following statements about proteasome is correct?
(A) In the cell, the proteasome is usually encapsulated in the lysosome.
(B) The 26S proteasome of eukaryotic cells is better at breaking down proteins with less than 4 ubiquitins than those with more ubiquitins.
(C) The core part of the 26S proteasome is the 20S tubular structure, which is responsible for catalyzing the breakdown reaction of proteins.
(D) The 20S component also possesses an ATPase activity, which is used to provide the catalytic energy required for decomposing the target protein.
(E) The 19S portion of the 26S proteasome is responsible for adding ubiquitin to the protein to be broken down.