Cells

• Plant cell


  • Cell membrane - responsible for determining which bits going in and out of the cell
  • Cell wall - important for structure
  • Vacuole - important for structure
  • Cytoplasm - where most of the reactions take place
  • Ribosomes - responsible for protein synthesis
  • Chloroplasts - green bits
  • Mitochondria - pink ones, where energy is produced
  • Nucleus - control center of the cell
• Animal cell

  • Cell membrane - controlling what goes in and out
  • Mitochondria - where energy is produced
  • Ribosomes - responsible for protein synthesis
  • Cytoplasm - where most of the reactions take place
  • Nucleus - where the DNA's hold, the control center of the cell
• There are several features of a plant cell that an animal cell doesn't share, for example, the cell wall, the vacuole, the chloroplasts.
• Bacterial cell

  • Cell membrane - controlling what goes in and out
  • Cytoplasm - where most of the reactions take place
  • Chromosome - DNA not in a nucleus
  • Flagella - used for locomotion
  • Ribosomes - for protein synthesis
  • Cell wall - on the outside
• Microscopy techniques have varied wildly over the time, from the very, very basic starts where you had your lenses and you had to use the focus to see what was going on, to ones that you're probably more familiar with in school which have slightly more sophisticated lenses, to the massive ones that I used to work on, electron microscopes, where they're all controlled by computer.
• Magnification

  Equals image height over object height
• DNA

  A long strand of deoxyribonucleic acid, made of lots of letters: As, Ts, Cs and Gs, that twist round into a double helix, which is still ridiculously long, so it further twists round so that it's in a chromosome, located in the nucleus of a cell
• Mitosis

  1. DNA in the nucleus needs to condense into chromosomes

  2. Chromosomes line up down the middle

  3. Checks take place to make sure the chromosomes aren't gonna go astray

  4. Chromosomes are pulled apart to either end of the cell

  5. New nuclei will form

  6. Two identical daughter cells separate
• Stem cells

  Cells that have the potential to turn into any other type of cell, with a number of different uses such as treating Parkinson's disease, brain or spinal injury, bone injuries, organ failure
• Making stem cells

  1. Take a nuclei out of an egg cell

  2. Take nuclei from the patient's cell and insert that into the empty egg

  3. Egg can then start to develop into an embryo

  4. Stem cells are then removed from the embryo and turned into new cells
• This does come with quite a lot of controversy because human embryos are going to be created and then destroyed, and there were lots of religious objections to this, people just saying that life starts when embryos are created, and people who object to the destruction of embryos.
• Diffusion

  The movement of gases or any particles that dissolved in solution moving down a concentration gradient from a high concentration to an area of low concentration
• Diffusion in the lungs

  • Carbon dioxide diffuses from the blood into the lungs so they can be breathed out, and oxygen diffuses from the lungs into the blood so it can be taken around the body
• Diffusion in the gut

  • Digested food moves from the gut cavity into the blood so that it could be taken around the rest of the body
• Osmosis

  The movement of water through a partially-permeable membrane from the area of high water concentration to an area of low water concentration
• Active transport

  The movement of substances across a membrane from a low concentration to a high concentration against the concentration gradient