Some terms used in the study of cells Amino acids are the building blocks of proteins.
Chromosomes are threadlike structures inside each cell.
They are made up of chromatin, a substance that contains protein and DNA, the cell's hereditary material. Cytoplasm is all the material inside the cell membrane except the nucleus. Cytoskeleton is a network of proteins that gives a cell its shape and moves structures in the cell cytoplasm. In some cells, the cytoskeleton helps the whole cell to move. Endoplasmic reticulum is a complex network of membranes in the cytoplasm.