You would know that a cell under microscope is prokaryote because it lacks nucleus cells. Prokaryote is a single celled organism. It’s cell structure is composed of flagellum, cell membrane, cell wall, cytoplasm, ribosome, nucleoid, and glycocalyx. Flagellum’s function is to aid cellular locomotion but is only for selected types of prokaryotes. Cell wall covers the outer part to protect the bacteria cells. Nucleid is the area that contains the DNA of the bacteria. Cell membrane regulates the flow of the substances in and out of the cell. Cytoplasm contains salts and other organic molecules. Ribosomes is responsible of protein production.