Internal structure of prokaryotes

Internal structure of prokaryotes

1. plasma membrane

   • functions : - selectively permeable membrane,,
   • assist in DNA replication
   • carry on respiration

2. cytoplasm

   • major structures in the prokaryotic cytoplasm are DNA, ribosomes and inclusions.
   • houses all chemical and component in prokaryotes
   • Thick, aqueous, semitransparent and elastic.

3. nuclear area

   • contain small circular double stranded DNA called plasmid
   • Single long circular molecule of double-stranded DNA (bacterial chromosome).
   • do not include histones and not surrounded by nuclear envelope.

4. ribosomes

   • site of protein synthesis
   • consists of 2 subunits : large and small subunit
   • Each subunit consists of protein and RNA called ribosomal RNA or rRNA.
   • can be inhibited by certain antibiotics

5. inclusions

   • reserve deposit
   • can serve as a basis of identification
   • Types of inclusions: a. Metachromatic granules b. Polysaccharide granules c. Lipid inclusions d. Sulfur granules e. Carboxysomes f. Magnetosomes g. Gas vacuoles

6. endospore

   • resting structures formed by some bacteria for survival during adverse environmental conditions
   • cannot be destroyed easily, even by harsh chemicals.
   • Spores are very impermeable to dye. However, they can be stained with special dye, Malachite green