Flashcards in Practical 1 - Spectrophotometry and Electrophoresis Deck (10)
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1
Define electrophoresis
Method of analysing molecules based on charge, by measuring their migration in an electric field.
2
Define spectrophotometry
Method of analysing molecules based on their spectral properties
3
What is absorbance?
Fraction of incident light absorbed by a solution which is measured.
Absorbance = log10 (light transmitted through blank solution/light transmitted through test solution)
4
At which wavelength is there maximum haemoglobin absorption?
540nm. Light is green at this wavelength
5
What does addition of sodium dithionite do to haemoglobin?
Removes oxygen
6
What does oxygen binding grant Hb?
Altered e- resonance, so different absorption spectrum to other proteins
7
Methaemoglobin?
Hb with Fe3+ instead of fe2+, caused by oxidation.
This is what gives dried blood its brown colour.
8
What is the Beer-Lambert Law?
A = E x c x I
Absorbance = Extinction coefficient x concentration x path length.
Basically says that the absorbance of a solution is proportional to the concentration of the absorbing solute and to the distance travelled by light through the sample.
It can be used to determine Hb conc in a sample using spectrophotometry results
9
Which is more negatively charged. HbA or HbS?
HbA is more negative
10