Cell Membrane Transport PDF

Course Requirements Recitation Mini quizzes Long quiz Exam Performance Tasks: Take-Home Laboratory Experiments General Biology 11/2 Science, Technology, Engineering, and Mathematics REVIEW Structure and Functions of the Cell Membrane General Biology 11/2 Science, Technology, Engineering, and...

Course Requirements Recitation Mini quizzes Long quiz Exam Performance Tasks: Take-Home Laboratory Experiments General Biology 11/2 Science, Technology, Engineering, and Mathematics REVIEW Structure and Functions of the Cell Membrane General Biology 11/2 Science, Technology, Engineering, and Mathematics  Learning Competencies At the end of the lesson, you should be able to do the following: Describe the structural components of the cell membrane; and Relate the structure and composition of the cell membrane to its function. 4 Structural Components of Plasma Membrane How do biologists describe the plasma membrane? 5  Structural Components of Plasma Membrane Phospholipid Bilayer The aqueous nature of the intracellular and extracellular environments energetically favors the formation of the phospholipid bilayer. The presence of double bonds in fatty acids helps maintain membrane fluidity. 6  Structural Components of Plasma Membrane Phospholipid Bilayer prevents the membrane from becoming too fluid at Molecules Embedded higher temperatures in the Membrane Membrane Proteins prevents the membrane from Cholesterol becoming too solid at lower temperatures Carbohydrate Chains 7  Structural Components of Plasma Membrane Phospholipid Bilayer Molecules Embedded in the Membrane Membrane Proteins Carbohydrate Chains The unicellular amoeba is capable of moving using its pseudopods or false feet because of the natural fluidity of the plasma membrane. 8  Structural Components of Plasma Membrane Membrane Proteins Transport Adhesion Recognition Receptor 9  Structural Components of Plasma Membrane Phospholipid Bilayer Glycolipid Glycoprotein Carbohydrate (Carbohydrate + Lipid) (Carbohydrate + Protein) Carbohydrate Lipid Molecules Embedded Protein in the Membrane Membrane Proteins Carbohydrate Chains The carbohydrate chains occur only on the outside surface of the lipid bilayer or on the peripheral proteins. 10 Plasma Membrane 11 How does the plasma membrane permit certain molecules to enter selectively into the cell? 12 Cell Transport Mechanisms: Active and Passive Transport General Biology 11/2 Science, Technology, Engineering, and Mathematics  Learning Competency At the end of the lesson, you should be able to do the following: Explain the transport mechanisms in cells (passive transport, and active transport). Lesson Objectives: Explain the difference between diffusion and osmosis as molecules cross the membrane. Differentiate hypotonic, isotonic, and hypertonic solutions for animal and plant cells. Explain how molecules are being transported across the membrane through facilitated transport. Explain how active transport moves substances across a membrane. Compare the movement of active transport from osmosis and diffusion. 14 15 How does diffusion affect the movement of substances into and out of the cell? 16  Simple Diffusion P A S S I V E Diffusion involves the movement of molecules in a solvent from an area of higher solute concentration to an area of lower solute concentration which Transport eventually results in the state of dynamic equilibrium. 17 D Simple Diffusion Facilitated Diffusion I F F U S no energy high to low required concentration I O passive movement of state of dynamic N transport molecules equilibrium 18 D Simple Diffusion Facilitated Diffusion I F The channel protein F facilitates the movement of molecules hence the term U “facilitated diffusion”. S I O N 19  F A Glucose Transporters Ion Channels C I L I T A T E D A change in the conformation of the carrier protein or transporter transports glucose across the membrane. Transport 21  Cell’s Transport Mechanism II F A Glucose Transporters Ion Channels C I L I T A T E D Ion channels are usually gated. They will open Transport when certain conditions are met. 23 How does osmosis play an important role in different cellular processes? 24  Movement is from the O region of high water concentration to one S Semi-permeable with lower water M membrane concentration. O S I Low water, high S High water, low solute solute concentration concentration 25  Isotonic Hypotonic Hypertonic O S relative concentration ability of a surrounding solution to cause a cell of solutes in fluids M to gain or lose water O S Tonicity I depends on the can be isotonic, S concentration of hypotonic, or solutes hypertonic 27  Isotonic O S solute solute M molecules molecules inside the cell O outside the cell S I Isotonic solution Solutions of equal solute S concentration 28  Hypotonic Isotonic Hypertonic O S solute solute M molecules molecules inside the cell O outside the cell S I Hypotonic solution has lower solute concentration and S has higher water concentration (i.e., less solute, more water). 29  Isotonic Hypertonic O S solute solute M molecules molecules inside the cell O outside the cell S I Hypertonic solution has higher solute concentration S and has lower water concentration (i.e., more solute, less water). 30 O S M O S I S 31  Check Your Understanding Classify the following situations based on the tonicity of the surrounding environment. Write if it is isotonic, hypotonic, or hypertonic. 1. It can be observed that plants wilt and are almost dying along a salted roadside. 2. Paramecia live in freshwater environments and use their contractile vacuoles to get rid of excess water. 3. Some animals must drink the saltwater to get the water into their bodies, but they maintain it by making the salts concentrated and excreted from the body. 32  It is a cellular transport mechanism that A involves the movement of molecules against C their concentration gradient with energy T expenditure. I V Cells that perform active transport have a E relatively large number of mitochondria. This is very evident and important in muscle cells Transport and nerve cells of the body. 33  Sodium-Potassium Pump A C T I V E Transport 34  Sodium-Potassium Pump Calcium Pump A C T Calcium Pump I V E Transport 35  Check Your Understanding Identify the correct term being described by each of the following statements. 1.These channel proteins transport certain ions across the membrane. 2.This protein transports glucose molecules from the intestinal epithelium to the underlying tissues and bloodstream. 3.This protein moves sodium ions (Na+) to the outside of the cell and potassium ions (K+) to the inside of the cell. 36 Bulk or Vesicular Transport General Biology 11/2 Science, Technology, Engineering, and Mathematics How do large molecules such as proteins pass through the cell? 40 Learning Competency At the end of the lesson, you should be able to do the following: Explain the transport mechanisms in cells (bulk or vesicular transport). 41  Bulk or Vesicular Transport Vesicles These are structures within or outside a cell, consisting of a cytoplasm and enclosed by a lipid bilayer. These are formed naturally during the process of secretion, uptake, and transport of molecules. Structure of a vesicle 42 How are the types of vesicular transport different from one another? 44 General Mechanism of Bulk Transport Exocytosis Types of Phagocytosis Vesicular Transport Pinocytosis Receptor- mediated endocytosis 45  Types of Vesicular Transport Exocytosis Types of Phagocytosis Vesicular Transport Pinocytosis Receptor- mediated endocytosis 46  Types of Vesicular Transport Exocytosis Types of Phagocytosis Vesicular Transport Pinocytosis Receptor- mediated endocytosis 47  Types of Vesicular Transport Exocytosis Types of Phagocytosis Vesicular Transport Pinocytosis Receptor- mediated endocytosis 48  Types of Vesicular Transport Exocytosis Types of Phagocytosis Vesicular Transport Pinocytosis Receptor- mediated endocytosis 49