Cells ( Paper 1 )

• Animal Cells -

  • Cell membrane
  • Nucleus
  • Mitochondria
  • Ribosomes
  • Cytoplasm
• Plant Cells -

  • Cell membrane
  • Nucleus
  • Mitochondria
  • Ribosomes
  • Cytoplasm
  • Cell Wall
  • Chloroplasts
  • Permanent Vacuole
• The function of the Cell Membrane is to control what enters and leaves the cell
• The function of the Cytoplasm is the site of the chemical reactions in the cell
• The function of the Mitochondria is the site of Respiration and where energy is released
• The function of the Ribosomes is to make proteins for protein synthesis
• The function of the Nucleus is to store the genetic information of the cell ( DNA )
• The function of the Chloroplasts is to absorb light energy for photosynthesis ( contains green pigment called chlorophyll )
• The function of the Cell Wall is to provide strength and support to the cell
• The function of the Permanent Vacuole is to maintain the shape of the cell and to provide support ( contains cell sap )
• There are 5 types of specialised cells
• There are 5 types of Specialised Cells:

  • Sperm Cell
  • Nerve Cell
  • Red blood Cell
  • Root Hair Cell
  • Muscle Cell
• The function of a Sperm Cell is to fertilise an ovumn (egg)
• The function of a Muscle Cell is to contract and relax to allow movement
• The function of a Red Blood Cell is to transport oxygen around the body
• The function of a Root Hair Cell is to absorb water ( by osmosis ) and absorb mineral ions ( by active transport )
• The function of a Nerve Cell is to carry electrical impulses around the body
• Sperm Cell Adaptations:

  • tail to swim to ovum
  • lots of mitochondria - release energy used to swim to the ovum
  • enzymes in head - breaks down egg for fertilisation

  
• Red Blood Cell Adaptations:

  • no nucleus so more room to carry oxygen
  • contains haemoglobin that binds to oxygen molecules
  • bi-concave to increase surface area

  
• Muscle Cell Adaptations:

  • contains protien fibres
  • lots of mitochondria for respiration - energy released used for muscle contractions

  
• Nerve Cell Adaptations:

  • branched endings (dendrites) - receive many nerve impulses
  • long and thin - electrical impulses sent round the body really quickly

  
• Root Hair Cell Adaptations:

  • large surface area
  • thin cell walls - shorter path for diffusion

  
• Eukaryotic Cells: Plant and Animal Cell

  • Has membrane bound organelles
  • Larger than Prokaryotic Cell
• Prokaryotic Cells: Bacteria Cell

  • Has no nucleus
  • Has no membrane-bound organelles
  • Smaller than Eukaryotic Cell
• Bacteria Cell -

  • Cell membrane
  • Cell wall
  • Cytoplasm
  • Flagellum (tail) - to swim
  • Plasmids (DNA) - extra DNA
  • Ribosomes
  • DNA loop - genetic information
• Diffusion: The movement of particles from an area of high concentration to an area of low concentration
• Osmosis: The movement of water particles from an area of high concentration to an area of low concentration through a partially permeable membrane
• Active transport: The movement of particles from an area of low concentration to an area of high concentration against a concentration gradient