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Concentration of Diluted Solution from Absorbance

The following questions refer to an experiment measuring the effect of pH on the activity of a particular enzyme. It is important that you fill out (on paper) ALL of the tables that will be presented since you will need the completed tables for later questions. This experiment was set up by incubating the enzyme in buffers of different pH, with a substrate that produced a yellow product (2-nitrophenol) when broken down by the enzyme. The final volume of the enzyme/buffer/substrate mixture was 5.0 ml and the incubation temperature was 37 ^oC. The intensity of this 2-nitrophenol was measured using a colorimeter after an incubation time of 10 min. In order to quantify the amount of product formed, a calibration curve was first performed where solutions of different concentrations of 2-nitrophenol were made and their absorbance determined using the same colorimeter. The stock solution of the 2-nitrophenol was 15.0 µM and it was diluted as follows:

(edited 10 years ago)

Reply 1

phaseshift

Original post by Otee

OK... and? What do you need help with?

You should attempt any questions before hand and show us your logic before we can do much, otherwise, it's not exactly a learning experience.

Reply 2

Otee

Well I divided 15uM (stock concentration) by 6 (amount of times diluted) to achieve 2.5uM per tube. I added 2.5uM to every tube to complete the table. Would this be correct?