LESSON 5 - Transport Mechanisms.pptx

Transport Mechanisms in Cell Ms. Mary Janelle F. Rodriguez LEARNING COMPETENCIES After studying these chapters, the students shall be able to: 1. Describe the structural components of the cell membrane 2. Explain transport mechanisms in cells (diffusion, osmosis, facilitated transport,...

Transport Mechanisms in Cell Ms. Mary Janelle F. Rodriguez LEARNING COMPETENCIES After studying these chapters, the students shall be able to: 1. Describe the structural components of the cell membrane 2. Explain transport mechanisms in cells (diffusion, osmosis, facilitated transport, active transport). 3. Differentiate exocytosis and endocytosis. STRUCTURE OF A CELL MEMBRANE In all organisms, cell membranes are lipid bilayers made up mostly of phospholipids. The polar head of a phospholipid interacts with water molecules; the nonpolar fatty acids tails do not. Because of these properties, they organize themselves as a lipid bilayer sheet or LEARN MORE bubble in a liquid medium LEARN MORE LEARN MORE STRUCTURAL COMPONENTS OF THE CELL MEMBRANE 1. Cell Membrane Lipids A. Phospholipids are a major component of cell membranes. Phospholipids form a lipid bilayer in which their hydrophilic (attracted to water) head areas spontaneously arrange to face the aqueous cytosol and the extracellular fluid, while their hydrophobic (repelled by water) tail areas face away LEARN MORE from the cytosol and extracellular fluid. LEARN MORE STRUCTURAL COMPONENTS OF THE CELL MEMBRANE 1. Cell Membrane Lipids B. Cholesterol is another lipid component of animal cell membrane. Cholesterol molecules are selectively dispersed between membrane phospholipids. This helps to keep cell membranes from becoming stiff by preventing phospholipids LEARN MORE from being too closely packed together. LEARN MORE STRUCTURAL COMPONENTS OF THE CELL MEMBRANE 1. Cell Membrane Lipids Glycolipids are located on cell membrane surfaces and have a carbohydrate sugar chain attached to them. They help the cell to recognize other cells of the body. LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE LEARN MORE  Self-Assessment Questions 01 1. Imagine a hypothetical cell with a higher concentration of glucose inside the cell than outside. Answer the following questions about this cell, assuming all transport across the membrane is passive, not active. a) Can the glucose simply diffuse across the cell  Self-Assessment Questions 01 b) If there are glucose transport proteins in the cell membrane, which way would glucose flow-into or out of the cell? Explain your answer. c) If the concentration of glucose was equal inside and outside of the cell, do you think there would be a net flow of glucose across the cell membrane in one