Suppose you perform a serial dilution of Amylase from a stock solution with a concentration of 500ug/mL. In five tests tubes you add 4mL of water. Then you aliquot 1mL of the stock solution into test tube 1 and vortex. From there you aliquot 1mL from test tube 1 into test tube 2. You continue to mix this way into each consecutive test tube. What is the final concentration in test-tube 3?

The final concentration in test-tube 3 is = 4ug/mL

Explanation:

Dilution factor = V initial / V final

Concentration of Stock solution = 500 ug/mL

5 test tubes are prepared with 4 mL of water

1 ml of stock solution is added to the 1st test tube.

therefore, the total volume of 1st test tube is = 4 ml + 1 ml = 5ml

∴ the concentration of 1st Test tube →

 C = m/V   [m= mass (solute) , v= volume]

     =500 ug / 5 ml  = 100 ug/ml

From 1st test tube, 1 ml is taken out and that is added to the 2nd  test tube.

∴ the concentration of 2nd Test tube = 100 ug / 5ml

                                                                = 20 ug/ml

From  2nd test tube, 1 ml is taken out and that is added to the 3rdd  test tube.

∴ the concentration of 3rd Test tube = 20 ug / 5ml

                                                              = 4 ug/ml

The final concentration in test-tube 3 is = 4ug/mL

the transfer of energy between two molecules spaced just nanometers apart plays a key role in many technologies, including photovoltaics, quantum information systems, lighting, and sensors, as well as in biophysics to measure nanometer distances and in photosynthesis. but an open question in this area is what effect, if any, the surrounding photonic environment has on this nanoscale energy transfer. by designing and performing a carefully controlled experiment to answer this question, scientists have settled the debate and found clues to improving the efficiency of many of the technologies that rely on this process.

explanation:

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.