Cell fractionation Flashcards
What is cell fractionation
A process where cells are broken up and the different organelles they contain are separated on their mass using gravity
How many processes are there and what are they each called
- Homogenisation
- Filtration
- Ultracentrifugation
Before cell fractionation occurs what must the solution conditions be
Isotonic (Same water potential)
Buffered
Ice cold
Why must the solution be ice cold
To reduce the activity of enzymes that could break down useful cell organelle
Why must the solution be buffered
Prevents organelle proteins from bbeing int denatured
Why must the solution be isotonic
To prevent cells being destroyed by osmosis
What happens during the homogenisation ( First stage )
Cell membrane / wall is cut so the organelles are released and revealed
What happens during the homogenisation ( First stage )
Cell membrane / wall is cut so the organelles are released and revealed
What happens during filtration (Second stage)
The homogenise is filtered through a gauze so it is separated from the cytoplasm so we only get the organelles
What happens during filtration (Second stage)
The homogenise is filtered through a gauze so it is separated from the cytoplasm so we only get the organelles
What happens during ultracentrifugation (Third stage)
Spin at low speed to separate most dense organelle first (Nucleus) so it moves to the bottom and becomes the pellet. The other organelles above it are called the supernatant
Order of density of organelles
Nuclei Naughty
Chloroplasts Cats
Mitochondria. Might
Lysosomes. Like
Endoplasmic Reticulum EaRning
Ribosomes Rewards
What do you do if you don’t want nuclei organelles and want chloroplast or other organelles
You separate the pellet nuclei to the supernatant and spin the supernatant again at a higher speed to than before to make chloroplast the pellet and other organelles the supernatant and you repeat this for the different organelles
