Studying cells

• What are the 3 steps of differential centrifugation?

  1. cell fractionation
  2. filtration
  3. ultracentrifugation
• What is the purpose of isolating organelles?

  to study them individually
• What are the 3 features of the solution used in cell fractionation?

  • ice cold
  • isotonic
  • buffer
• Why does the solution need to be ice-cold?

  • less kinetic energy so enzymes do not break down organelles
• Why does the solution need to be isotonic?

  same water potential as inside organelles so there is no osmosis to prevent bursting and damage
• Why does the solution need to be a buffer?

  maintains the PH to prevent proteins in organelles from denaturing
• What is cell fractionation?

  process of breaking down the cell membrane to release organelles
• What is used for cell fractionation?

  homogeniser
• What is used for ultracentrifugation?

  Centrifuge
• What property of the organelles is used to separate them?

  Density
• Organelles from most dense to least dense

  Nuclei, chloroplasts, mitochondria, lysosome, ER, ribosomes