Internal structure of prokayote

Internal structure of prokayote

1. Plasma membrane

   • The movement of materials across membrane
     • Passive diffusion
       • Materials move along concentration; ATP is not needed
         • Simple diffusion
         • Osmosis
         • Facilitated diffusion
     • Active diffusion
       • Material move against concentration; ATP is needed
         • Active transport
         • Glucose translocation
   • Structure
     • Phospholipid bilayer with embedded protein
   • Function
     • selective barrier
     • synthesize cell wall component
     • respiration
     • DNA replication
     • ATP
   • Mesosome

2. Plasmid

   • small, circular stranded DNA
   • Do not contain essential DNA
   • replicate independently of chromosomal DNA

3. Ribosome

   • 70S ( 30S small subunits + 50S large subunits)
   • The site of protein synthesis
   • Each subunit consists of protein
   • can be inhabited by antibiotics

4. Cytoplasm

   • 80% water
   • mainly contain DNA, ribosomes and inclusions
   • Intracytoplasmic membrane

5. The nuclear area

   • Nucleoid
     • single long circular double-stranded DNA molecules
     • no histones
     • no nuclear envelope

6. Inclusions

   • Metachromatic granules
     • Stain red with methylene blue
     • known as volutin
       • polyphosphate used in the synthesis of ATP
     • also found in algae, fungi, protozoa
   • Polysaccharide granules
     • Contain glycogen and strach
       • stained by using iodine
         • reddish brown- glycogen
         • blue - strach
   • lipid inclusions
     • stained with sudan dye
     • storage materials
       • poly-beta-hydoxybutyric acid
   • Sulfur granules
     • Energy reserve
       • oxidising sulfur and sulfur-containing substance
   • Carboxysomes
     • used for carbon fixation during photosynthesis
     • contain ribulose 1,5- diphosphate carboxylase
   • Magnetosomes
     • sense the magnetic field of the earth
     • protect the cell against hydrogen peroxide accumulation
     • found in aquatic bateria
   • Gas vacuoles
     • covered by protein
     • appeared bright and refractile area under microscrope
     • found in photosynthetic group
     • function
       • provide buoyancy for aquatic prokaryotes

7. Endospores

   • Spores that formed within the cells
   • can stained with Malachite green
   • involved in the transmission of some diseases to human
   • protect DNA
   • served as carbon and energy sources during germination