Medical Interventions (MI)1.2Parts of a Bacterial Cell

Nucleoid

1.) In a bacteria cell, DNA stays in this central region. Bacterial DNA is not held in a nucleus as in plant and animal cells; instead, it gathers and clumps together toward the center of the cell. 2.) The DNA-containing area of a bacterial cell.

Pili and fimbriae

1.) These structures allow bacteria to attach to different surfaces, including other cells. Also, they can serve as a 'bridge' between two bacteria over which genetic information can be exchanged. 2.)These hollow, hairlike structures made of proteins allow bacteria to attach to other cells. The sex pilus allows the transfer of plasmid DNA from one bacterial cell to another.

Ribosome

1.) This structure can be found on the endoplasmic reticulum or floating in the cytoplasm. They follow instructions from the nucleus and create proteins the cell needs. 2.) Protein synthesis takes place in this structure. Messenger RNA is "read" by this structure and amino acids are assembled into a complete protein chain based on the RNA sequence.

Flagellum

1.) This structure helps a bacterial cell move around. They each have a 'motor' at their base, which makes them rotate. Some bacteria only have one, while others have many. 2.) The purpose of this structure is motility. They are long appendages which rotate by means of a "motor" in the cell envelope. Bacteria may have one, a few, or many of these structures in different positions on the cell.

Plasma membrane

1.) This structure is one of the outer layers of a bacterial cell. Like a doorman, it controls what nutrients, ions, and waste enter and leave the cell. 2.) The semipermeable limiting layer of cell protoplasm consisting of a fluid phospholipid bilayer with intercalated proteins.

Cell wall

1.) This structure maintains the shape of the cell, just like the scaffolding in a building. In a bacterial cell, this structure does not prevent molecules from entering or leaving the cell. 2.) The permeable wall surrounds the plasma membrane and encloses and supports the cell.

Capsule

1.) This structure protects bacterial cells from harm. 2.) This layer of polysaccharide (sometimes proteins) protects the bacterial cell and is often associated with pathogenic bacteria because it serves as a barrier against phagocytosis by white blood cells.

Plasmid

Small circular DNA fragments found in the cytoplasm that contain code responsible for antibiotic resistance and other characteristics. These structures, along with their associated traits, can be transferred between bacteria, even from one bacterial species to another.

Endotoxin

They are structures of the outer membrane of the cell wall of a gram-negative bacteria. They are invariably associated with gram-negative bacteria whether the organisms are pathogenic or not. Its function is to act as a protective permeability barrier. The outer membrane is impermeable to large molecules and hydrophobic compounds from the environment.