Electrotaxis? Paramecium-electricity-migration.

[Bonsay]

Homework Statement

You put an anode and a cathode on two different sides of a container fulled with water and paramecia. When you start the current (1,5V), the paramecia "swim" to the negative pole- cathode, where they appear to be unharmed and continue to swim about locally. When you switch the cathode with the anode, they die.

Question1: Why do they move?
Question2: Why do they die?

optional question:If my memory serves me right, the bubbles only appeared on the cathode during the experiment. Is this supposed to happen or did I just forget?

Homework Equations

The Attempt at a Solution

Apparently this is galvano/elecrotaxis? The bubbles that appear on the cathode are hydrogen molecules, and the ones on the anode are oxygen molecules. If this is electrotaxis then there must be something beneficial where they are migrating or something threatening where they are migrating from? Or is this just a response to the electromagnetic field and the movement is out of their control?

Thanks and hello (I'm new :P).

 

[nate808]

Hello! It's great to have a new scientist in our forum. Let me try to answer your questions.

Question 1: The paramecia are moving due to a phenomenon called electrotaxis. This is a response to the electromagnetic field created by the anode and cathode. The paramecia are negatively charged and are attracted to the positively charged cathode, causing them to move towards it.

Question 2: When you switch the cathode with the anode, the paramecia die because they are exposed to a high concentration of oxygen bubbles. These bubbles are created at the anode due to the electrolysis of water, and the high concentration of oxygen becomes toxic to the paramecia, causing them to die.

Optional question: Yes, the bubbles appearing on the cathode during the experiment is a normal occurrence. As mentioned before, these bubbles are hydrogen molecules created through electrolysis. This is a common phenomenon in electrochemistry experiments.

I hope this helps answer your questions. Keep up the good work in your scientific explorations!

 

[Blueshift5]

Hello and welcome! I would approach this phenomenon with a series of experiments and observations to understand the underlying mechanisms that are causing the paramecia to move and die in response to the electric current.

Regarding the first question, the movement of the paramecia towards the negative pole (cathode) can be explained by electrotaxis. This is a phenomenon where organisms, such as paramecia, respond to an electrical field by moving towards the source of the current. It is believed that this is a survival mechanism, as the movement towards the cathode may provide some benefits to the paramecia, such as a more favorable environment or nutrients.

For the second question, the reason for the death of the paramecia when the cathode and anode are switched could be due to the build-up of toxic byproducts at the anode. As you mentioned, oxygen bubbles are produced at the anode, which could lead to an increase in the concentration of oxygen in the water. This could be harmful to the paramecia, leading to their death. Further experiments could be conducted to confirm this hypothesis.

As for the optional question, the appearance of bubbles only on the cathode is expected, as hydrogen gas is produced at the cathode during electrolysis. This is a normal occurrence in electrolytic cells.

Overall, the phenomenon you observed is very interesting and could be further investigated to understand the underlying mechanisms and potential applications in fields such as bioelectronics and biotechnology. Keep exploring and asking questions!