these densities are all significantly lower than 1.570 , which is characteristic of the mature large subunit of cytoplasmic ribosomes , suggesting that the precursor particles have a relatively higher ratio of protein to rna , and that ribosome maturation involves , in addition to decrease in the size of the rna molecules , a progressive decrease in the proportion of associated protein .
C0010834
cytoplasmic
C0035553
ribosome