photometry essay plan Flashcards
1
Q
intro - what is the princple?
A
optical density is measured by passing beam of white (visible) light
amount of absorbance is measured
2
Q
main body - example and hows it done
A
e.g. bradford assay - measures protein conc
- reagent added
- reaction= mixture undergoes optical change
- Conc of substance measured - beer lamberts law
use spectrophotometer
3
Q
what is beer lambers law
A
conc of substance is directly proportional to light absorbed
conc of substance is inversely proportional to log of transmitted light
4
Q
conclusion - why do we use photometry?
A
quick and easy
cheap
reproducible results
most labs have spectrophotometer
