A)N-terminal signal sequences have been determined to be necessary for ER import because if they are added to sequences which are not normally targeted to the ER,they will end up in the ER.
B)Signal recognition particles (SRPs)are needed during co-translational import.
C)Ribosomal translation of a 6-12 amino acid sequence on the N-terminus will initiate the process through interactions with SRP.
D)GTP hydrolysis by the Sec61 translocon causes ribosomal translation to begin again after it is halted by SRP binding.

A)Ribosomes and mRNA are incubated with microsomes,then a protease is added and the results are analyzed.
B)Ribosomes and mRNA are incubated with microsomes,then a protease and detergent are added and the results are analyzed.
C)Ribosomes and mRNA are incubated with protease,then microsomes are added and the results are analyzed.
D)Ribosomes and mRNA are incubated with microsomes,then detergent is added and the results are analyzed.