The ribosomes are granular structures which may line the endoplasmic reticulum attach to the nuclear membrane or float free in the cytoplasm. Through an electron microscope, ribosomes look like tiny dark dots. The job of the ribosomes is to help make proteins. They combine smaller amino acid units into longer protein chains using chemical instructions from the nucleus. The proteins then help the cell to grow or are used to control chemical reactions that make everything happen in the cell.