AP BIOLOGY

Detailed explanation-1: -The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.

Detailed explanation-2: -To build proteins, the two ribosomal subunits, small and large, assemble together to form the complete ribosome. It has binding sites for mRNA and transfer RNA (tRNA) molecules. The large subunit sits on top of the small subunit, with the mRNA template sandwiched in between the two.

Detailed explanation-3: -The nucleolus is a spherical structure found in the cell’s nucleus whose primary function is to produce and assemble the cell’s ribosomes.

Detailed explanation-4: -Ribosomes are mostly constructed in the cell nucleus, but the final stages of assembly occur in the cytoplasm of the cell.

Detailed explanation-5: -The rough ER, which is covered by ribosomes on its outer surface, functions in protein processing. The smooth ER is not associated with ribosomes and is involved in lipid, rather than protein, metabolism.