I think the most appropriate answer is: the solvent being used in the experiment <span>To correct for any light absorption not originating from the solute you will need to calibrate the tools with a solution that most similar to the sample. Blank covete or standard solution can be used, but it was not ideal. By using the solvent as calibration, you can remove the reading from the solvent so your result only comes from the sample.
The cell membrane performs those functions. It is the outer layer of a cell and it creates a barrier, regulates material entry and exit, uses chemical signals, and creates structure.
