What are the key features of bacterial cell structure?

Bacterial cells are characterised by their lack of nucleus, presence of a cell wall, and their small size.

Bacterial cells, unlike plant and animal cells, are prokaryotic, meaning they do not have a nucleus. Instead, their genetic material is found in a single, circular strand of DNA located in the cytoplasm. This is a key feature of bacterial cells and is one of the main ways they differ from eukaryotic cells.

Another defining feature of bacterial cells is their cell wall. This rigid structure surrounds the cell membrane, providing protection and maintaining the shape of the cell. The cell wall is made of a substance called peptidoglycan, which is unique to bacteria. This feature is particularly important as it is the target of many antibiotics, which work by disrupting the formation of the cell wall, causing the bacteria to burst and die.

Bacterial cells are also typically much smaller than eukaryotic cells. They usually range in size from about 0.5 to 5 micrometres in diameter, while eukaryotic cells are typically 10 to 100 micrometres. Despite their small size, bacteria are incredibly diverse and can be found in a wide range of shapes, including spheres, rods, and spirals.

In addition to these features, many bacteria also have additional structures that aid in their survival and reproduction. These can include flagella, which are whip-like structures used for movement, and pili, which are hair-like structures used for attaching to surfaces and for exchanging genetic material with other bacteria. Some bacteria also have a capsule, a layer outside the cell wall that provides additional protection.

In summary, the key features of bacterial cell structure include their lack of a nucleus, the presence of a cell wall made of peptidoglycan, their small size, and the potential presence of additional structures like flagella, pili, and capsules. These features are fundamental to the survival, reproduction, and diversity of bacteria.