What is the effect of lead nitrate on the cell membrane of a beetroot cell?

If you search our site for <beetroot> and for <lead> you will find some relevant information.

As you know, lead is a "heavy metal" and these are well known non-reversible inhibitors of enzymes. Now, the carrier proteins in cell membranes have some very similar properties to enzymes, so lead will prevent carrier proteins from operating and the membrane will lose its ability to be selective in its transport of materials. Lead will inhibit enzymes in the cell - eg enzymes involved in the process of respiration (so energy release will be knocked out).

As the concentration of lead increases, I would expect the membrane to possibly lose its integrity (it might physically be destroyed enough to prevent even osmosis taking place).

I doubt whether you will get up to a concentration where the osmotic concentration of the lead nitrate will become important - the membrane will have ceased to function before such concentration is reached.

John Hewitson