The document describes the main organelles found within cells and their functions. The cytoplasm surrounds the organelles and contains proteins and minerals. The cell membrane protects the cell and is semipermeable. The nucleus controls all cell functions and stores DNA. The endoplasmic reticulum forms proteins and lipids. Ribosomes form proteins while the Golgi apparatus processes and delivers them within the cell. Mitochondria supply energy to the cell through ATP production. Lysosomes contain enzymes to break down bacteria, viruses, and worn out cell parts.