By Levi Clancy for Student Reader on
Hypothesis: Transport system is enzymatic.
Experiment: Show saturation effect.
We incubate a culture in labeled solute. After incubation, we wash away supernatent and measure the concentration of labeled solute in our cells at various time points. Over time, more and more solute will be taken up by the cells. We then incubate a culture with very little labeled solute. There are two possibilities:
There is less solute taken up when there is less solute available. This means that transport is passive.
The amount of solute taken up is the same. This means that the transport is enzymatic.
To find out which kind of enzymatic transport is used, you can treat Gram (-) cells with lysozyme. This allows binding proteins to escape, which causes ABC transport to cease.