Photographs of cells magnified 40,000 to 50,000 times show tubelike structures in the cytoplasm. The ER at times connects with the cell membrane or with the nuclear membrane. The ER changes constantly and is a place where many cells substances are made. They are so small they can be seen only with an electron microscope. Ribosomes are the sites in cells where proteins are made.
Proteins are large, complex substances that are building blocks of living substances.
Robosomes are made within the nucleolus in the nucleus of a cell. The ribosomes pass out of the nuclear membrane into the cytoplasm. Some form long strings in the cytoplasm. They both produce proteins. Golgi bodies store and release chemicals in the cell.