What are the structural features of prokaryotic cells?

Structural features of prokaryotic cells include: 

• Capsule - Present in some prokaryotic cells, the capsule is a sticky outermost layer made up of polysaccharides. It protects the cell’s interior, helps maintain the cell’s shape, assists in retaining water so the cell doesn’t dry out, and prevents the cell from bursting when it takes up excess water. 
• Cell Wall – The cell wall may be the outermost covering of the cell (when the capsule is absent) or it may be located under the capsule when it is present. It is made up of peptidoglycan. When the capsule is absent, the cell wall performs its functions. It protects the interior of the cell, maintains the cell’s shape, and prevents the cell from bursting when it takes up water. 
• Cytoplasm: Cytoplasm is a gel-like substance that is enclosed by the cell membrane, which lies just under the cell wall. It is composed mainly of water that also contains salts, enzymes, cell components, and a variety of organic molecules.
• Cell Membrane or Plasma Membrane – The cell membrane lies between the cell wall and the cytoplasm. Made up of phospholipid, the cell membrane helps to regulate the flow of substances in and out of the cell. 
• Nucleoid Region – The nucleoid region is the area of the cytoplasm that contains the single circular DNA molecule. 
• Ribosomes – These are cell organelles that are responsible for synthesis of proteins. 
• Plasmids These are circular DNA structures that carry genes but are not involved in reproduction.
• Flagella – Appearing as fine, long, whip-like protrusions, flagella assist in cellular locomotion. 
• Pili – Pili appear as fine hair-like structures on the cell’s outermost surface. They help bacterial cells attach to each other. 
• Fimbriae – These thin filaments help in adhesion. They help prokaryotic cells stick to surfaces and objects in their environment.