Question

name __________ date ________ concept covered: the cell membrane 1. what are the functions of the cell membrane? ________ 2. the cell membrane is said to be “selectively permeable.” what does this mean?________ 3. scientists today use the “fluid mosaic model” to describe the structure of the cell membrane. define “fluid mosaic model.” __________ 4. draw a simple sketch of the cell membrane. show the arrangement of each of the following: phospholipids, integral proteins, peripheral proteins, transport proteins, and carbohydrates. be sure to label each part of your drawing.

Explanation:

1. The cell - membrane functions include protecting the cell, regulating the movement of substances in and out of the cell (selective permeability), and facilitating cell - cell recognition and communication.
2. Selective permeability means that the cell membrane allows certain substances (such as water, oxygen, and some ions) to pass through while restricting the passage of others (like large molecules and some polar substances).
3. The fluid mosaic model describes the cell membrane as a fluid structure with a "mosaic" of various components. The phospholipid bilayer is fluid, allowing the movement of proteins and other molecules within it. The "mosaic" aspect refers to the diverse arrangement of proteins (integral, peripheral, and transport), carbohydrates, and lipids in the membrane.
4. Since this is a drawing task, a text - based response cannot be provided for the actual sketch. But in a sketch, the phospholipids would be shown as a double - layer with hydrophilic heads facing outward and hydrophobic tails facing inward. Integral proteins would span the entire membrane, peripheral proteins would be attached to the surface, transport proteins would have openings for transporting substances, and carbohydrates would be attached to proteins or lipids on the outer surface of the membrane.

Answer:

1. Protects the cell, regulates substance movement, and aids in cell - cell recognition/communication.
2. Allows certain substances to pass while restricting others.
3. A fluid structure with a diverse arrangement of proteins, carbohydrates, and lipids in a phospholipid bilayer.
4. (Sketch description provided above for guidance on drawing)