Cell membranes are important because they protect the cell and control the materials that flow in and out of it. Lipids are needed in order to create the membranes in the cell.
<h2>
Answer</h2>
Buffer controls the sudden change in the solution
<h2>
Explanation</h2>
Buffer prevents the sudden change in the pH. They keep the pH of the solution nearly constant. For example, in human Buffer solution helps to regulate the pH of human blood. The normal pH of the human blood is nearly 7.35 to 7.45 and a little change in this pH many leads the serious problems. Carbonic and bicarbonate buffers play a role in maintaining the acid base balance of the blood.
The cell membrane. (It also could be cytoplasm because it supports the organelles. But I think it is the cell membrane because it says barrier, and the cell membrane is the cell's barrier between it and the outside of the cell.)
The cell membrane is the outer most layer of the animal cell. It is selectively permeable, so it lets good things in and keeps bad things out. It also helps larger things that the cell needs to get in such as glucose by the process of endocytosis.
The answer to the question is c
