AP BIOLOGY

Detailed explanation-1: -Endoplasmic reticulum is a network of membranes inside a cell through which proteins and other molecules move. Proteins are assembled at organelles called ribosomes.

Detailed explanation-2: -In eukaryotes, ribosome assembly is a complex process involving more than 200 assembly factors and spreads from the nucleolus to the cytoplasm. The process starts with the synthesis by the RNA Pol-I of the 35S pre-rRNA, which is co-transcriptionally bound and folded by ribosomal proteins and assembly factors.

Detailed explanation-3: -If DNA is the blueprint, then ribosomes are the masons-they build the protein using amino acids as the ‘bricks’. 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.

Detailed explanation-4: -Definition. The nucleolus is a spherical structure found in the cell’s nucleus whose primary function is to produce and assemble the cell’s ribosomes. The nucleolus is also where ribosomal RNA genes are transcribed.

Detailed explanation-5: -Ribosomes are mostly constructed in the cell nucleus, but the final stages of assembly occur in the cytoplasm of the cell.