This is what I learned about what the function of membranes is. I learned that the plasma membrane is composed of phospholipids. This plasma membrane is what holds the contents of a eukaryotic cell inside the cell. I learned that proteins are what allows the membranes to perform certain functions and these proteins also help cells communicate with one another. I also learned that membranes can permit certain substances and deny others access to the interior of the cell.
What I have found difficult about what I have studied are the contents in section 6.3. Some concepts I can understand but others such as hypertonic, hypotonic, and isotonic go right over my head. Also, I simply have no idea how to understand the pictures on pg. 120. After reading it several times, the whole idea seems to completely evade me.
Structure is related to function in cell membranes because membranes give the cell its rigid form and the membrane also serves as a regulator, allowing only certain substances inside the cell. This mean that the plasma membrane is very fluid and is constantly moving, allowing for substances to pass through in the first place. This membrane or boundary, holds many proteins that perform specific functions for the cell. Also, because the unique structure of the plasma membrane, the proteins that are lodged in the membrane are able to communicate with other cell's proteins.