bio mine

• Parts of an animal cell

  • Cell membrane
  • Cytoplasm
  • Ribosomes
  • Nucleus
  • Mitochondria
• Cell membrane function


  Control the entry and exit of substances into the cell
• Cytoplasm function


  Where chemical reactions happen inside the cell
• Ribosome function


  Protein synthesis - make proteins
• Nucleus function


  Control the cell activities
• Mitochondria function


  Where aerobic respiration happens to provide energy for the cell
• Plant cells also have a nucleus, ribosomes, and mitochondria
• Additional parts of a plant cell


  • Chloroplasts
  • Vacuole
  • Cell wall
• Chloroplast function


  Absorb light energy for photosynthesis
• Vacuole function


  Support the cell structure
• Cell wall function


  Provide strength, made of cellulose
• Both animal and plant cells are classified as eukaryotic cells - have a nucleus</b>
• Prokaryotic cells


  Cells without a nucleus, e.g. bacteria
• Parts of a bacterial cell

  • Cell membrane
  • Cytoplasm
  • Flagellum
  • Plasmids
  • Ribosomes
  • Chromosome
• Flagellum function


  Used for moving/swimming
• Plasmids


  Small extra loops of DNA that often contain useful genes like antibiotic resistance
• Bacterial cell wall


  For structure and protection, not made of cellulose
• prokaryotic cells have no mitochondria chloroplasts and no nucleus
• plant cells and prokaryotic cells: both have a
• Specialized cells


  Cells that change their size, shape and internal structures to carry out specific functions
• Plant specialized cells


  • Root hair cells
  • Xylem
  • Phloem
• Cell differentiation


  The process where different genes are turned on/off in cells to change their shape and structures, allowing them to become specialized
• Stem cells


  Undifferentiated cells that can differentiate into different cell types
• Plant cells can differentiate throughout their life, animal cells mostly differentiate early and then just divide by mitosis
• Optical/light microscope


  Uses light to magnify images, can see nucleus and mitochondria
• Electron microscope


  Has much higher magnification and resolution, can see smaller structures like ribosomes
• Preparing a microscope slide

  1. Add drop of water

  2. Add thin piece of tissue (e.g. onion skin)

  3. Stain with iodine

  4. Lower coverslip

  5. Place on microscope stage

  6. Start at lowest power lens

  7. Use coarse focus to focus

  8. Increase magnification power

  9. Use fine focus to focus at higher magnification
• Chromosomes


  Coiled structures containing DNA, arranged in pairs in the nucleus
• Cell cycle


  The process a cell goes through to prepare for and undergo cell division (mitosis)
• Mitosis


  The process of one cell dividing into two genetically identical daughter cells
• Stem cell types


  Embryonic, adult stem cells, meristem
• Therapeutic cloning can produce stem cells genetically identical to the patient
• There are ethical issues around using embryonic stem cells
• Diffusion


  The net movement of particles from an area of high concentration to an area of low concentration
• Stem cells


  Cells that can be grown into different types of cells, e.g. blood cells, nerve cells, pancreatic cells
• Using embryonic stem cells

  Raises ethical issues as the embryo cannot consent
• Using adult stem cells


  Avoids ethical issues as the person can consent
• Unused embryos being destroyed is not accepted by some people as they view the embryo as potential life
• There is a risk of viral infection or cancer when using stem cells as they can divide rapidly
• Diffusion


  The net movement of particles from an area of high concentration to an area of low concentration, a passive process that does not require energy