Ribosome , site of protein synthesis. Contains both rRNA and proteins, can be free floating or attached to endoplasmic reticulum. Golgi apparatus , associated with ER in the cytoplasm, for packaging and export of materials. A stack of membranes that can package and secrete, among other things, glycoproteins for the plasma membrane and lysosomes. Lysosomes , in the cytoplasm, are membrane-surrounded pockets of digestive enzymes.
Lysosomes can help break down food vesicles or can be used to recycle the cell's contents.
Mitochondria are double-membraned. The inner membrane is highly folded for more surface area for energy-producing reactions. 3 Cytoskeleton , or lattice-like network of filaments throughout the cell for support. 3,5 Centrioles . Centrioles are microtubule structures that assist in cell division in animal cells.