Chapter 5, Problem 25RQ

Summary Introduction

To draw: A diagram of an epithelial cell that is capable of absorbing Na⁺, but lacks the ability to absorb water.

Introduction: A cell membrane is a semi-permeable membrane which allows the entry of a few molecules that are small in size. The larger molecules such as ions and proteins are transported to or from the cell through specialized gateways called channels. These channels have high specificity and allow the entry or exit of specific molecules.