Cell Fractionation Flashcards
What are the two stages of cell fractionation?
-Homogenisation
-Ultracentrifuging
What is cell fractionation?
The process of cells being broken up.
Wat solution must the cells be put into?
Cold, isotonic and buffered solution.
Why are the cells put in a cold solution?
To reduce enzyme activity.
Why are the cells put in an isotonic solution?
To prevent organelles from bursting/shrinking due to osmotic changes.
Why are the cells put in a buffered solution?
To maintain a constant PH to prevent proteins and enzymes from being denatured.
What are the steps of homogenisation?
-The cells are cut up and put into a cold, Isotonic, buffered solution.
-Cells are broken up using a homogeniser.
-Homogenate is filtered.
What happens when the cells are put in the homogeniser?
-Organelles are released from the cells.
-A liquid is produced called the homogenate.
Why is the homogenate filtered?
To remove any unbroken cells or large debris.
What are the steps of ultracentrifugation?
-The organelles spun at a low speed.
-When spun it forms a supernatant and a pellet.
-The supernatant is removed and the pellet is spun again at a higher speed.
-Then spun a final time at a higher speed again.
What is removed on the first spin?
The nuclei
What is removed on the second spin?
Mitochondria and chloroplasts
What is removed in the third spin?
Riobosomes
