About a week ago I began a school project in biology, where I was given the freedom to choose my own topic for experimentation. I wanted to test the effect of electricity on the growth of yeast cells. Im using optical density to measure the change in the yeast cell population of yeast - sucrose solutions that I have prepared in my school lab. After preparing the yeast - sucrose solution this is my proposed method:
Passing D.C electricity through each yeast solution:
The Voltage will be fixed at 6 V wile the current will be changed from 0.2 Amperes to 1.2 Amperes in steps of +0.2 A for each trial
Remove the napkin covering from the beaker to be tested
Adjust the voltage knob of the plugged in power box to 6V. Do NOT connect the wires while the box is switched on.
Place a hard cover with two holes over the beaker opening
Switch off the power box and connect a wire to each terminal (positive and negative) submerging the ends of the wires into the beaker solution through the hard cover
Switch on the power supply and adjust the current to 0.2 A
The yeast solutions must be subjected to the D.C supply for 10 minutes each.
After subjection, switch off the power supply, and remove the wire terminals from the solution
re - secure the top of the beaker
Repeat this procedure for the remaining 5 beakers in steps of increasing current by +0.2 A
Once completed, place all beakers back into the incubator at 30˚C, leave for 24 hours
After 24 hours, re - test the optical density of each as done in step III
Calculate the change in optical density for each of the yeast solutions.
Here is the problem that I face. The solution itself is not highly conductive. At best i can pass 0.01 Amperes through the solution and no more. Some people have suggested that I add salt to the solution to increase its conductivity but the problem with this is that the electrolysis reaction will produce chlorine gas (poisonous) and more importantly sodium that will react with the water and form sodium hydroxide. This would cause the pH of the solution to rise and would affect the growth of the yeast cells.
What can I do to increase the conductivity of the solution without having bi products from a electrolysis reaction that affect the growth of the yeast ?
Appreciate any help lol
Please ignore the electrolysis reaction that I provided as it is wrong as you will notice! Instead Hydrogen gas and Oxygen gas are produced not NaOH and Clorine gas. The water level goes down and this may also be a problem. What do you goys think about the overall procedure. Is it flawed?
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