Prokaryotes & Eukaryotes

• Eukaryotes cells contain genetic material in a nucleus. They are complex and relatively large. Plant and animals cells are eukaryotes cells.
• nucleus- the organism’s genetic material, arranged as chromosomes)
• Prokaryotic cells do not contain a nucleus. Their genetic material floats in the cytoplasm. They are simple cells , and are typically smaller than eukaryotes cells. Examples: bacteria
• What are bacteria?

  • Bacteria are the smallest living organisms.
  • They are unicellular organisms , which mean they consist of just one cell. Every single cell can carry out the seven life processes.
  • Movement , Reproduction , Sensitivity , Growth , Respiration , Excretion , Nutrition.
• MRS GREN- 7 Life processes

  1. M- movement
  2. R- respiration
  3. S -sensitivity
  4. G- growth
  5. R- reproduction
  6. E- excretion
  7. N- nutrition
• Bacteria cells have different shapes. However, they all contained a…

  • Cell membrance
  • Cell wall
  • Genetic material
• 1. Cytoplasm = a ”jelly like” substance where chemical reactions happen.
  2. Genetic material = floats freely in the cytoplasm. This is normally circular.
  3. Plasmids = a circular piece of DNA that is used to store extra genes. These genes are normally not needed but it is where antibiotic resistance genes are normally found.
  4. Pili = tiny “hair like” structure that enable the cell to attach to structures and are also used to transfer genetic material between bacteria.
  5. Flagella = ”tail like” structures that allow the cell to move through liquids.

  
• Bacteria structure with extra sub cellular structures part 2

  • F. Slime capsule = this layer is outside the cell wall. It protects a bacterium from drying out and from poisonous substances. it also helps bacteria to stick to smooth surfaces
  • G. Cell wall = made of peptidoglycan which holds the cell together and protects it
  • H. Cell membrane = a barrier that controls which substances enter and leaves the cells