Prokaryote

• Prokaryotic cells:

  Prokaryotic cells do not contain a nucleus and are 0.1-10 micrometres in size, which is smaller than eukaryotic cells. They are single celled and you are unable to view the internal structures of them on a light microscope due to them being so tiny.

  Examples of eukaryotic cells includes bacteria and archaeans.
• ultrastructure of prokaryotic cells

  
• Structures of a prokaryotic cell:

  Ribosomes, plasmid, cell wall, cell membrane, nucleoid, slime capsule, cytoplasm, flagella.
• Structure and function of a ribosome within a prokaryotic cell:

  Structure -> float freely within cytoplasm, have no membrane, smaller than eukaryotic ribosomes, 60% RNA and 40% proteins. There are two subunits;50s and 30s. The 50s contain 2 RNA's (23s and 5s), and 34 proteins. The 30s contains 16s RNA's and 21 proteins.


  Function -> The ribosome is the site where proteins are made via protein synthesis.
• Structure and function of the plasmid in a prokaryotic cell:

  Structure -> A small loop of DNA.

  Function -> DNA storage, carries genes that may benefit the survival of organisms. They may also provide antibiotic resistance to some if not most bacterias.
• Structure and function of cell walls in prokaryotic cells:

  Structure -> surrounds the prokaryotic cells and is made up of peptidoglycon.

  Function -> protects and supports the cells.
• Structure and function of the cell membrane in a prokaryotic cell:

  Structure -> Have a plasma membrane.

  Function -> Controls what enters and leaves the cells. It is also a site for metabolic reactions like cellular respiration.
• Structure and function of the nucleoid in a prokaryotic cell:

  Structure -> Irregularly shaped region of the cell, made up of nuclear material, has no membrane, DNA forms in a circular chromosome.

  Function -> Stores densely packed genetic material and controls cellular activity.
• Structure and function of the slime capsules in a prokaryotic cell:

  Structure -> Slippery layer outside the cell wall of some bacteria.

  Function -> Prevent desiccation (drying out), protects the prokaryote by providing protection to the bacteria from wbc.
• Structure and function of the cytoplasm in a prokaryotic cell:

  Structure -> Made up of gel-like cytosal water based solution. Contains ions, small molecules and macro molecules. T cytoplasm is the site of almost all cellular activity in a prokaryotic cell.

  Function -> Houses and maintains optimal environment for cellular organelles.
• Structure and function of the flagella/flagellum in a prokaryotic cell:

  Structure -> Like cilia but longer, stick out from the cell surface. Have a plasma membrane, it is located inside the cell and is connected to the microtubules in the centre.

  Function -> Microtubules contract to form the flagellum which moves cells by propelling forward.
• Structure and Function of the Pili in the prokaryotic cell:

  Structure -> hair like structure like vili.

  Function -> required for the bacterial transfer.