Structure and Function Prokaryotic Cells Structure and Function

Prokaryotic Cell Structure On Your Own Annotate the diagram of a bacteria cell with the function of each structure. Indicate whether the structure is found in all or some prokaryotic cells.

Plasma (Cell) Membrane Controls passage of materials into and out of the cell All cells have a plasma membrane

Cytoplasm Fluid portion of all cells Location of cellular metabolism

Ribosomes Float freely in the cytoplasm of all cells The site of protein synthesis. Are 70S in prokaryotes, slightly smaller than the 80S ribosomes found in Eukaryotes. (S) stands for Svedberg units.

Nucleoid The glob of DNA in all prokaryotic cells Still a double helix Ends come together for form a circle Not wrapped around proteins as in eukaryotic cells (termed “naked DNA”). 6

Plasmid A small circle of DNA found in some prokaryotes that exists and replicates independently of the main DNA in the nucleoid. Often contain genetic instructions for resistance to antibiotics (antibiotics are chemicals that kill bacteria)

Some Prokaryotes have a cell wall Gives shape, support and protection to the plasma membrane and cytoplasm of the cell. Eubacteria wall made of peptidoglycan* (protein- sugar molecules). *different than plant cell walls, which are made of cellulose 8

Flagellum Some bacteria have one or more Used for motility.

Pili Short fibers projecting from the cell wall found on some bacteria. They may help the bacteria cling to surfaces.

Capsule A special mucus-like protective coating found on some disease-producing bacteria.

Prokaryotic cells do not have membrane bound organelles 12