The statement 'polypeptides in the ER are usually larger than polypeptides synthesized from the same mRNA that have not entered the ER' is false.
The rough endoplasmic reticulum is the site where polypeptides enter so that protein formation can take place. Apart from protein formation, polypeptides are needed for various other metabolic functions by the ER.
Those polypeptides that are smaller in size can enter the endoplasmic reticulum because of the entering space and the small size of the endoplasmic reticulum. On the other hand, the polypeptides that are large, although being synthesized from the same mRNA, stay outside as they cannot enter the ER due to their large size.
To learn more about the mRNA, click here:
brainly.com/question/24885193
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