Prokaryotic cells

• • They are simple in structure, with no membrane-organelles and fewer organelles than animal or plant cells.
  • contain plasmids which are small loops of DNA that provide an extra source of genetic information
  • Their DNA is not contained in a nucleus and is instead ‘free’ in the cytoplasm in the area called the nucleoid.
• features

  • capsule is made up of polysaccharides (complex sugars) that are hydrophilic (attracted to water). This prevents dehydration of the bacterium
  • cell wall is made up of peptidoglycan and has the function of protecting and supporting each cell
  • cell membrane is similar in structure to that found in a eukaryotic cell and has the same function of regulating which molecules can be transported in and out of the cell
• Cell wall

  made of peptidoglycan, provides support
• nucleoid

  • circular DNA in the cytoplasm not surrounded by a nuclear envelope
• 70 ribosomes

  • site of protein synthesis in the cytoplasm
• plasmid

  • small circular DNA in the cytoplasm that has genes promoting survival of bacteria
• flagellum

  • tail-like structure that rotates allowing the bacterium to swim