Membrane Function How does the cell membrane control movement of materials? Why? The membrane is critical to the maintenance of homeostasis in living organisms. The cell membrane sepa- rates the cell from the external environment and plays a critical role in regulating movement of material in and out of the cell. Additionally, cukaryotic cells are made complex by the presence of internal membranes that form organelles, so the cells may become specialized. These organelle membranes create compart- ments within the cell that can do specific functions. Model 1 - Types of Ions and Molecules in a Cell Type 1 lons Type 2 Molecules Type 3 Molecules Potassium: K+ Glucose: Water: ОН Type 4 Molecules Molecular oxygen (O): O=O H Sodium: Na Н OH Urea: H OH Carbon dioxide (CO): Calcium: Ca2+ H OH OH O=CO Chloride: CI H OH HN -NH₂ polar nonpolar small large 1. Consider the ions and molecules in Model 1. 4. Identify at least two substances that would need to move into a cell to maintain homeostasis. It would be molecule such as water and orgen b. Briefly explain why the cell needs each of the substances you identified in part a. Water for Hydrolysis, oxigen for respiration 2. Consider the ions and molecules in Model 1. 4. Identify at least two substances that would need to move out of a cell to maintain homeostasis. urea and carbon dioxide b. Briefly explain the source of the molecules you identified in part 4 3. Complete the table by labeling the types of substances as polar or nonpolar and large or small.
