Science Buddies: "Ask an Expert"

Hello,

I have question and I'm not sure if what i'm going to say can really happen, but if I put a plant cell in a solution of 1 mM of HCl, will the cell wall dissolve or partially break? If that happens, can I use DNA extracted from the same type of cell in order to repair the damage?

Thanks

Hi,

Living cells operate by means of proteins that are translated from DNA. If you expose a cell to 1 mM HCl for long enough the proteins as well as the lipid membranes will be destroyed. No repair process can put it back together at that point.

Can you be a little clearer on what question you are trying to ask? DNA is the source of all the proteins in an intact cell, but once the cell membrane is broken, the cell is dead. If you want to study repair of damage you need to expose cells to something like UV or a pH that is not too low, like 5.0, so that the cells remain intact and functional.

Give us some more information about the project you are planning and we can help you better.

Sybee

Thank you very much for your reply,

I have already thought about working with DNA, and now I have changed my point of view. Now, what I would like to test is, if possible, how the rate of Photosynthesis increases once the cell wall of a plant cell is damage. I'm interested in this because I have read that the cell wall is made of cellulose, which is a polysaccharide, and since photosynthesis helps to produce sugars once the Calvin cycle occurs, then I would like to see if the rate of photosynthesis increases as there is a need for plants to restore the cell wall of their cells. What I would like to use to intentionally damage the cell wall is an acid, but preferably a solution of 1 mM acetic acid since that is a weak acid.

Thank you

Hi,

Your reasoning about the rate of photosynthesis being coordinated with a need for cellulose in a plant is good but I am afraid that damaging a cell with acid, even a weak acid, may also harm the chloroplasts where photosynthesis occurs. If the photosynthetic machinery is damaged then the rate will decrease, not increase.

How did you plan to expose plant cells to the acid? How will you measure the rate of photosynthesis?

Have you thought about doing experiments a with green alga such as Chlorella? Chlorella grows as single cells in water with a few nutrients and its rate of photosynthesis can be measured by how much oxygen it produces over a certain period of time. You could simply add some acid to the culture to lower the pH and measure the effect on photosynthesis. Proving a connection between cell damage and increased photosynthesis would be difficult, however.

Post again with some details about your experimental plans and we will try to help you set up the best conditions.

Sybee