Answer:
control which substances enter the cell
Step-by-step explanation:
According to this question, scientists in year 1800s studied how fat-soluble substances and water-soluble substances interact with cell membranes. Cell membrane is a cellular structure found in every living cell whose function is to demarcate the interior of the cell from the external environment.
Based on the study, cell membrane interacts with water-soluble and fat-soluble substances in order to control which substances can enter the cell. The cell membrane is selectively permeable meaning that not all substances passes through it into and out of the cell.