Flashcards
3.1 Methods of studying cells
Cards in this deck (10)
- 1Resolutionthe minimum distance apart that two objects can be in order for them to appear as separate items
- 2Resolution of Light and Electron microscopes?Light - 0.2 µm
Electron - 0.1 nm / 0.0001 µm - 3Magnificationincreases the size of an image, does not always increase resolution
- 4Magnification of Light and Electron microscopes?Light - x1500
Electron - x500,000 - 5What is Cell Fractionation?the process where cells are broken up and the different organelles they contain are separated out
- 6Before cell Fractionation, tissue is placed in a Solution which is ; 3Cold ❄- reduce enzyme activity, that might break down the organelles
Same Water Potential (as Tissue) - prevent organelles bursting or shrinking due to osmotic gain or loss of water
Buffered - pH does not fluctuate, which could alter structure of organelles or effect enzyme functioning - 7What is Homogenation?Cells are broken up by homogeniser
- >releases organelles from cell
Homogenate (resultant fluid)
-> filtered to remove complete cells or large pieces of debris - 8What is Ultracentrifugation?Fragments in the filtered homogenate are separated in a Centrifuge (which spins tubes of homogenate at very high speeds to create centrifugal force)
- 9Ultracentrifugation for animal cells ?1. homogenate spun at low speed -> heaviest organelles (nuclei) forced to bottom, forming thin sediment or pellet
2. Supernatant (fluid at top) removed and spun at faster speed -> next heaviest organelles (mitochondria) form sediment
3. process continues with increasing speed and seperated - 10Advances in biological knowledge?Allowed detailed study or structure and functions of isolated compounds.
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- GCSE Biology (Cells) Flashcards on 3.1 Methods of studying cells, created by Sea Chel Pie on 29/09/2018.
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