AP BIOLOGY

Detailed explanation-1: -The ribosome is a complex molecule made of ribosomal RNA molecules and proteins that form a factory for protein synthesis in cells. In 1955, George E. Palade discovered ribosomes and described them as small particles in the cytoplasm that preferentially associated with the endoplasmic reticulum membrane.

Detailed explanation-2: -rRNAs are found in the ribosomes and account for 80% of the total RNA present in the cell. Ribosomes are composed of a large subunit called the 50S and a small subunit called the 30S, each of which is made up of its own specific rRNA molecules.

Detailed explanation-3: -Ribosomes are complexes of rRNA molecules and proteins, and they can be observed in electron micrographs of cells.

Detailed explanation-4: -The structure that is made of rRNA and proteins is the ribosome. Ribosomes are protein factories inside the cell. They can either be free floating in the cytoplasm or attached to the endoplasmic reticulum to produce secreted proteins or proteins for the endomembrane system.

Detailed explanation-5: -Ribosomal RNA (rRNA) molecules are the structural components of the ribosome. The rRNAs form extensive secondary structures and play an active role in recognizing conserved portions of mRNAs and tRNAs. They also assist with the catalysis of protein synthesis.