The document describes the structure and function of various organelles in eukaryotic and prokaryotic cells. It discusses the nucleus, nucleolus, rough endoplasmic reticulum, smooth endoplasmic reticulum, ribosomes, Golgi apparatus, mitochondria, chloroplasts, lysosomes, cytoplasm, cytoskeleton, cell membrane, cell wall, and vacuoles. The key functions covered include storing DNA, producing proteins and ribosomes, intracellular transport, energy production, photosynthesis, digestion, structural support, selective permeability, and storage of materials. The document provides information on these cellular components for plant, animal, and prokaryotic cells.