The cell membrane is also called the plasma membrane and is mainly composed of a phospholipid bilayer. Some of the functions of the cell membrane include protecting the cell from the environment, giving shape to the cell, allowing transportation of materials in and out of the cell, and allowing for cell recognition. The structure of the cell membrane is known as the fluid-mosaic model - as you read ahead, think about why we call it this! 

1. What is another name for the cell membrane? 

2. What is the main component that makes up the layers of the cell membrane? 

3. Describe the functions of the cell membrane.n