B1.1b(sub-cellular structures of eukaryotes and prokaryotes)

• Eukaryotic cells


  cells of animals, plants and fungi
• Prokaryotic cells


  Cells of bacteria
• Nucleus


  • Found in both animal and plant cells
  • Controls the activities of the cell
  • Contains genetic material (DNA)
  • The DNA is organised into chromosomes
• The cell membrane


  
  

  • Found in both animal and plant cells
  • Selective barrier (semi permeable) that controls the passage of substances into and out of the cell
  • Contains receptor molecules
• The cytoplasm


  • Found in both animal and plant cells
  • Where most of the chemical reactions in the cell take place
• The vacuole


  
  

  • Found in plant cells
  • surrounded by a membrane
  • filled with a fluid called cell sap to keep the cell turgid
  • vacuoles are permanent structures in plants
  • Animal cells may also have vacuoles, but these are small and temporary
• The chloroplasts


  • Are found in plant cells above ground
  • contain chlorophyll that absorbs the light the plant needs for photosynthesis
• Cell walls (in plants)


  
  

  • an additional layer outside the membrane
  • made from cellulose fibres
  • These fibres provide strength
  • unlike the cell membrane, it does not regulate what enters or leaves the cell (freely permeable)
• The mitochondria


  • found in animals and plants
  • contain enzymes for cellular respiration
  • where most respiration occurs
  • where energy is released from the glucose in the food we digest
• Ribosomes


  • Found in both animals and plants
  • Where protein synthesis occurs
• Chromosomal DNA


  • Found in bacterial cells
  • The DNA of bacterial cells found loose in the cytoplasm
  • Not contained within a nucleus
• Plasmid DNA


  • Found in bacterial cells
  • Small, closed circles of DNA
  • Present in the cytoplasm
  • Unlike chromosomal DNA, plasmid DNA can move from one bacterium to another giving variation
• Flagella


  • Found in bacterial cells
  • Bacteria can have one or more flagella
  • Flagella can rotate or move in a whip like motion to move the bacterium
• Cell walls (in bacteria)


  • Bacterial cell walls provide structure and protection
  • They are NOT made of cellulose like cell walls in plants
• Sub-Cellular structures of a bacterial cell

  The sub-cellular structures of a bacterial cell:

  A) Chromosomal DNA

  B) Plasmid DNA

  C) Flagellum

  D) Cell membrane

  E) Cell wall

  
• Sub-Cellular structures of an animal cell

  The sub-cellular structures of an animal cell:

  A) Cytoplasm

  B) Nucleus

  C) Ribosome

  D) Mitochondrion

  E) Cell membrane

  
• Sub-Cellular structures of a plant cell

  The sub-cellular structures of a plant cell:

  A) Cytoplasm

  B) Nucleus

  C) Ribosome

  D) Vacuole

  E) Mitochondrion

  F) Cell membrane

  G) Cell wall

  H) Chloroplast

  
• Sub-Cellular structures that animals and plants have in common

  Animal and plant cells have certain structures in common:

  • the nucleus
  • cell membrane
  • mitochondria 
  • ribosomes