Unit 1 - Topic 1 - Laboratory Techniques for Biologists - Section B - Liquids and solutions Flashcards
1
Q
What is linear dilution?
A
Dilutions in a linear dilution series differ by an equal interval, for example 0·1, 0·2, 0·3 and so on.
2
Q
What is log dilution
A
Dilutions in a log dilution series differ by a constant proportion, for example 10-1,10-2, 10-3 and so on.
3
Q
How is a standard curve produced and what is it used for?
A
Plotting measured values for known concentrations to produce a line or curve allows the concentration of an unknown to be determined from the standard curve.
4
Q
What is a buffer and what does it do?
A
Addition of acid or alkali has very small effects on the pH of a buffer, allowing the pH of a reaction mixture to be kept constant.
5
Q
Method and uses of a colorimeter
A
- Calibration with appropriate blank as a baseline;
- use of absorbance to determine concentration of a coloured solution using suitable wavelength filters:
- use of percentage transmission to determine turbidity, such as cells in suspension.