Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Aim: How does the structure of the cell membrane contribute to its function? Do Now: Describe the function of the cell membrane. HW: page 199 #29 What is the function of the structure below? • CONTROLS what enters and exits the cell. • provides protection and support. Cell membrane Structure • Phospholipids • Proteins Label the diagram: • The cell membrane is composed of a special type of lipid (fat) called a phospholipid. PHOSPHOLIPID BI-LAYER Proteins Membrane Proteins: 1. Structural Proteins: 2. Transport Proteins: (Channels) 3. Receptor Proteins 4. Enzymes STRUCTURAL PROTEIN CHANNEL Receptors RECEPTORS Receptors found on the cell surface aid in cell to cell communication. Messengers (hormones) from other cells bind to these receptors (based on shape) and transfer information. Why is this model called the fluid mosaic model? + = Fluid because the molecules are always changing position with each other and mosaic because it is made of different kinds of molecules. How is the cell membrane different from an umbrella? An umbrella is impermeable It does not allow materials through How is an umbrella different from a window screen? The window screen is permeable It allows materials through How is a window screen similar to the cell membrane? The cell membrane is semi-permeable -it allows certain materials through What will get through the cell membrane? What is the difference between these molecules? Can the elephant get into the house? Do all things get through the cell membrane? NO!!! The cell membrane is selectively permeable Why do some things get through the cell membrane? Small molecules are more likely to get through the cell membrane compared to big molecules What can pass through the cell membrane? • • • • • • CO2 O2 H2O Glucose Starch Charged particles (Na+)