STRUCTURES OF THE CELL MEMBRANE Upload “2.16 Structures of the cell membrane notes” to eBackpack Learning Target: Interpret cell diagrams- know the function of each structure.

Use the picture to determine one of the functions of the cell membrane. What is the scientific term that is used to describe this function? Selective Permeability

Relate the selective permeability of a tea bag to a cell membrane

Review Importance Why is selective permeability important to the cell? Homeostasis- the proper balance of nutrients and gases are maintained within the cell

How do the cell membrane structures result in selective permeability?

The phospholipid layer ( the cell membrane’s basic framework) A phospholipid consists of a polar portion, called the head, and two longer fatty acids, called the tail.

When mixed with water, the heads are attracted to polar water molecules (hydrophilic). The nonpolar tails move as far from water as possible (hydrophobic), and a double layer of phospholipids with tails to the interior results.

Function of the phospholipid layer Creates a soft, flexible, stable and fluid covering for the cell Fatty layer allows O 2 and CO 2 which are fat soluble to pass through. What would be the purpose of this? Impermeable to water soluble substances such as amino acids, sugar, protein, nucleic acids and various ions. What would be the purpose of this?

Relate the selective permeability of a tea bag to a cell membrane What passed out of the tea bag? What passed into the tea bag? What can pass across a cell membrane? Do substances that cross a cell membrane require energy?

There are two types of proteins in the cell membrane 1. Integral (transmembrane) proteins pass through the entire membrane 2. Peripheral proteins do not protrude into the phospholipid layer Some of the phospholipids and integral proteins have carbohydrate chains attached to them forming glycolipids and glycoproteins. Cholesterol is also found within the membrane of animal cells to provide support and structure Organic molecules in the cell membrane

Word Bank: Carbohydrate Chains, Cell Membrane, Cholesterol, Integral Protein, Peripheral Proteins, Phospholipids

Function of protein structures

Relate the selective permeability of a tea bag to a cell membrane What structures of the cell membrane are like the pores in the tea bag?

Cell Membrane Quiz

To do: Can you add any information to your cell model presentation?