lab 1 Flashcards
Prep for exam and review
Why does ‘osmotic shock have to be prevented’?
It leads to premature lysis of the plasma membrane or nuclear envelope.
How was ‘osmotic pressure’ Prevented ?
Wheat germ is treated with a buffer salt solution. This provides an isotonic environment for the cell.
Why were the germ cells not soaked in distilled water?
Cell would have swwelled up and brust as distilled water is isotonic.
Why are salts used to isolate DNA?
Dna is negatively charged, it has negatively charged backbone and the positively charged histones. To disrupt these bonds, introducting competing ions will result in disruption. When the interaction becomes high, histones will dissociate from DNA, and protein solubility decreases with high salt solutions they will precipitate.
Ex: Na+ will form ionic bond with negatively charged DNA while cl- with histones.
