IB Biology Topic A2.2.5: Prokaryote Cell Structure Key Definitions

70S ribosomes are small ribosomes found in prokaryotic cells, as well as in the mitochondria and chloroplasts of eukaryotic cells. They are responsible for protein synthesis, translating messenger RNA (mRNA) into functional proteins.

The cell wall is a rigid, protective layer located outside the plasma membrane of certain cells, including prokaryotes, plants, fungi, and some protists. It provides structural support, protection, and shape to the cell.

The cytoplasm is the jelly-like substance inside a cell, excluding the nucleus, where various cellular activities occur.

Naked DNA refers to DNA that is not enclosed within a nucleus or bound to histone proteins. It exists freely in the cytoplasm of prokaryotic cells, such as bacteria and archaea, and in some environments outside of cells.

The region of the cytoplasm where the circular prokaryotic DNA molecule is located

The plasma membrane is the thin, flexible boundary that surrounds a cell, separating its internal environment from the external surroundings. It is composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

A prokaryote is a single-celled organism that lacks a nucleus and membrane-bound organelles. Its genetic material is found in a single, circular DNA molecule located in the nucleoid region of the cell.