Bacteria cell (Prokaryotic)

• Nucleoid 


  • A single circular length of DNA is folded
  • The nucleoid ( meaning nucleus-like) is the irregularly shaped region that holds nuclear material without a nuclear membrane and where the genetic material is localised. The DNA forms one circular chromosome
  • Location of nuclear material within the bacterial cell but with no outer membrane. The DNA within the nucleoid consists of one circular chromosome.
• Ribosomes


  • Makes protein , 70s ribosomes are smaller and less active than 80s
  • Smaller than ribosomes found in eukaryotic cells. They consist of two sub-units and they are not surrounded by a membrane
  • Protein synthesis occurs at the ribosomes
  • Smaller than the 80S ribosomes of eukaryotes. Composed of two subunits. Joins amino acids to each other is a specific order to create proteins.
• Slime capsule


  • Polysaccharide layer outside the cell wall
  • Prevents the cell from drying out. Helps to protect from while blood cells, helps stick to surfaces
  • Slippery layer outside the cell wall of some species of bacteria
  • Protects the cell and prevents dessication
  • Surrounds the cell wall in some bacteria. Protects the cell – particularly the cell wall of Gram-negative bacteria from antibiotics. It is made of polysaccharides but also contains protein
• Plasmid 


  • Small loops of DNA
  • Plasmids carry genes that may benefit the survival of the organism
  • Small additional rings of DNA found in the cytoplasm of bacterial cells. They carry separate genes including those that give the bacteria anti-biotic resistance. They can be transferred from one bacterium to another. Used in genetic engineering.
• Cell wall 


  • Prokaryotic cells are surrounded by a cell wall made of peptidoglycan
  • Protects and supports each cell
  • Wall is made of peptidoglycan and gives the bacteria structure and protection
• Flagellum


  • A long hair-like structure which is used to propel the bacterium along.
• Pilus


  • Plural is pili. Used to help the bacteria to stick to surfaces. Sex pili are used to transfer genetic material from one bacterium to another.