Question

float around the cell membrane freely and thus, the cell membrane is often called a fluid - mosaic. the cell membrane also acts as the attachment point for both the cytoskeleton and, if present, the cell wall, both of which give a cell its structure and support. after reading, please watch the video “cell membranes are way more complicated than you think” by teded, then answer the following questions. (https://www.youtube.com/watch?v=nsklf1w4eok) 1. describe the role and importance of the cell membrane. what is meant by “the cell membrane is semipermeable?” 2. describe the basic structure of the cell membrane with regard to specific molecules: 3. why is the cell membrane often referred to as a “fluid - mosaic?” 4. what is the function and purpose of the proteins embedded in the cell membrane?

Explanation:

1. The cell membrane protects the cell, regulates substance - entry/exit (semi - permeable means it allows certain substances to pass while blocking others). It also provides attachment points for cytoskeleton and cell wall.
2. The cell membrane is composed of a phospholipid bilayer with hydrophilic heads and hydrophobic tails. There are also proteins, cholesterol, and carbohydrates embedded or attached.
3. It is called "fluid - mosaic" because the phospholipids and proteins can move laterally (fluid), and the membrane is a mosaic of different molecules like phospholipids, proteins, cholesterol, etc.
4. Embedded proteins in the cell membrane can act as transporters (facilitate substance movement), receptors (bind to signaling molecules), enzymes (catalyze reactions), and provide structural support.

Answer:

1. Role: Protects cell, regulates substance transport, provides attachment points. Semi - permeable: Allows certain substances through while blocking others.
2. Phospholipid bilayer with hydrophilic heads and hydrophobic tails, along with embedded/attached proteins, cholesterol, and carbohydrates.
3. Phospholipids and proteins can move laterally (fluid), and it is a mix of different molecules (mosaic).
4. Transporters, receptors, enzymes, structural support.