Membranes are essential components of all cells. The plasma membrane protects the integrity of the interior of the by allowing certain substances in, while keeping other substances out. NOTE Your written assignment should be submitted in a Word document (or similar program) and should be at least 2-3 pages in length, double-spaced with 1-inch margins, and written in Times New Roman size 12 font. You should provide a word count at the end of your written assignment. Cite any reference(s) you use in the preparation of your essay using proper APA format.
