INTERNAL STRUCTURE OF PROKARYOTES

INTERNAL STRUCTURE OF PROKARYOTES

1. STRUCTURE OF PROKARYOTES

   • • PLASMA MEMBRANE
       • The prokaryotic plasma membranes are composed of phospholipids bilayer with embedded proteins. In the middle of the bilayer, the fatty acids of the phospholipids are found, which is called as hydrophobic region. Prokaryotic cells can have multiple plasma membranes. In prokaryotic organisms, plasma membranes are responsible for controlling the entry and exit of the cell
       • • Functions
           • 1. Separate the cell from its outside environment
           • 2. Regulates what enter and out of the cell.
           • 3. Protecting the integrity of the interial of the cell
             • - allowing only selected substance into the cell and keeping other substances out.
           • 4. serves as a base of attachment for the cytoskeleton in some organisms and the cell wall in others
           • 5. The lipid bilayer is semi-permeable, which allows only selected molecules to diffuse across the membrane
             • https://www.youtube.com/watch?v=UgN76naeA1Q
     • CYTOPLASM
       • • gel-like, yet fluid, substance in which all of the other cellular components are suspended.
     • RiBOSOMES
       • protein builders or the protein synthesizers of the cell.
       • • when are ribosomes used in the process of protein synthesis?
           • when the cell needs to make a protein, mRNA is created in the nucleus
             • The mRNA is then sent out of the nucleus and to the ribosomes.
               • when it is time to make protein, the 2 sub units come together and combine with the mRNA.
                 • the 2 sub units lock onto the mRNA and start the protein synthesis.
     • INCLUSIONS
       • - nuclear or cytoplasmic aggregates of stainable substances, usually protein.
       • TYPES : 1. metachromatic granules 2. Polysaccharide granules 3. Lipid inclusion 4. Sulphur granules 5. Carboxysomes 6. Magnetosomes 7. Gas vacuoles
     • ENDOSPORE
       • https://www.youtube.com/watch?v=7zCQLITFEb0
       • a dormant, tough and non-reproductive structure produced by certain bacteria from the Firmicute phylum.
         • Special stain technique
           • Moeller stain : Allow the endospore to show up as red while the rest of the cell stains blue.
           • Schaeffer-Fulton stain : Stains endospore green and bacterial bodies red.
       • • FORMATION OF ENDOSPORE

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