Dilutions & Separation Techniques Flashcards
What formula is used to make a fixed amount of a dilute solution from a stock solution?
C1V1 = C2V2
What is V1?
The volume of stock solution needed to make the new solution.
What is V2?
The final volume of the new solution.
What is C1?
The concentration of stock solution.
What will a buffer do?
Control pH especially in proteins.
What does a colorimeter measure?
How much a solution will absorb in a particular wavelength.
What separation techniques are used by biologists?
- Filtration
- Fractional distillation
- Paper/thin layer chromatography
- Centrifugation
- Iso-electric point
What does filtration separate?
A solid from a liquid.
What does distillation use to separate substances?
Boiling point.
What does centrifugation use to separate substances?
Molecular weight.
What is the iso-electric point?
The pH at which a protein has no net charge.
What can be used as the defining value for proteins?
the iso-electric point.
How can IEP be calculated?
By using info on all of the amino acid/basic characteristics and their number in the protein.
It can also be measured using a gel set up with a pH gradient and measuring the pH the protein migrates to.
What is a linear dilution?
One where the dilutions differ by an equal interval.
What is a log dilution?
One in which the dilutions differ by a constant proportion.
How does a pH buffer allow the pH of a reaction mixture to be kept constant?
As the addition of acid or alkali have a very small effect on the buffer.
What is affinity chromatography used for?
To separate proteins.
How is affinity chromatography carried out?
A solid matrix of gel column is created with specific molecules bound to the matrix or gel. Soluble, target proteins in a mixture with a high affinity for these molecules become attached to them as the ,mixture passes down the column. Other non-target molecules with a weaker affinity are washed out.
