Delphinidin

Ribosomes are tiny bodies that are visible with the aid of an electron microscope. They are typically roughly ellipsoidal in shape with apparently varied and complex surfaces. Each ribosome is composed of two subunits that are composed of RNA and proteins; the subunits, upon close inspection, can be differentiated by a line or cleft toward the center. Ribosomes average only about 20 nanometers in diameter in most plant
cells. Unattached ribosomes often occur in clusters of five to 100, particularly when they are involved in linking amino acids together in the construction of the large, complex protein molecules that are a basic part of all living organisms.

Ribosomal subunits are assembled within the nucleolus, released, and in association with special RNA molecules, they initiate protein synthesis. Once assembled, complete ribosomes may line the outside of the endoplasmic reticulum but can also occur unattached in the cytoplasm, chloroplasts, or other organelles. About 55 kinds of protein are found in each ribosome of prokaryotic cells and a slightly higher number
in those of eukaryotic cells. Unlike other organelles, ribosomes have no bounding membranes, and because of this, some scientists prefer not to call them organelles.