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7.4 – Cellular Transport State Standards SB1a Explain the role of cell organelles for both prokaryotic & eukaryotic cells, including the cell membrane, in maintaining homeostasis & cell reproduction. SB1d Explain the impact of water on life processes (i.e. – osmosis/diffusion) Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Cellular Transport There are various mechanisms that transport materials in and out of the cell. All of them involve the plasma membrane and are at the heart of homeostasis. There are 2 types of movement across the plasma membrane: PASSIVE Transport and ACTIVE Transport Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Movement of particles across the cell membrane without using energy There are 3 types of passive transport: Diffusion Facilitated Diffusion and Osmosis Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport – Cont’d Type 1: Diffusion Movement of substances across the cell membrane from and area of high concentration to an area of low concentration. HIGH LOW Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Diffusion Cont’d Having different concentrations in different areas creates a concentration gradient, and molecules will naturally move from high to low. Students: Draw arrows on the diagram to show which direction the particles will move. 7.4 – Cellular Transport Passive Transport – Cont’d More Diffusion Pics Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Diffusion – Cont’d Dynamic Equilibrium The solute concentration is equal inside & outside the cell Molecules continue to move, but the overall concentration remains the same. Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport - Cont’d Type 2: Facilitated Diffusion Movement of materials across the plasma membrane through a protein THIS DOES NOT REQUIRE ENERGY! Chapter 7 Cellular Structure and Function Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Cont’d Type 3: Osmosis Diffusion of water across a selectively permeable membrane. Water will naturally move from where it is highly concentrated to where it is less concentrated. This does NOT require energy! Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Osmosis Cont’d Tonicity affects the movement of water Isotonic Solution – think “equal” Hypotonic Solution – low solute concentration Hypertonic Solution – high solute concentration Chapter 7 Cellular Structure and Function Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Osmosis Cont’d In an Isotonic Environment… Water and dissolved substances diffuse into and out of the cell at an equal rate. Plant Cell Blood Cell 11,397x Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Osmosis Cont’d MEMORIZATION TIP: “Hypo-Hippo” In a Hypotonic Environment… Solute concentration is higher inside the cell. Water diffuses into the cell. Plant Cell Blood Cell 13,000x Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Passive Transport Osmosis Cont’d MEMORIZATION TIP: “Salt Sucks” In a Hypertonic Environment… Solute concentration is higher outside the cell. Water diffuses out of the cell. Plant Cell Blood Cell 13,000x Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport A process that uses energy to move molecules across the cell membrane. There are 3 types of active transport: Active Transport using carrier proteins. Endocytosis Exocytosis Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport with Carrier Proteins Uses energy to pump molecules across the cell membrane from a region of lower concentration to a region of higher concentration. This movement goes against the natural concentration gradient. Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport Cont’d The Na+/K+ ATPase Pump Moves three sodium ions out of the cell and two potassium ions into the cell Use your prior knowledge: What is ATPase?? Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport Cont’d Endocytosis Process by which the cell uses energy to surround large particles and bring them into the cell Chapter 7 Cellular Structure and Function 7.4 Cellular Transport Active Transport Cont’d Exocytosis Secretion of a large amount of material out of the plasma membrane Chapter 7 Cellular Structure and Function 7.4 Formative Questions Which type of cellular transport does not require an input of energy? A. active transport B. endocytosis C. exocytosis D. facilitated diffusion Chapter 7 Cellular Structure and Function 7.4 Formative Questions How does osmosis occur between the two solutions separated by the selectively permeable membrane? Chapter 7 Cellular Structure and Function 7.4 Formative Questions A. Sugar moves to the left. B. Sugar moves to the right. C. Water moves to the left. D. Water moves to the right. Chapter 7 Cellular Structure and Function 7.4 Formative Questions Which diagram shows a cell in a hypotonic solution? A. B. C. Chapter 7 Cellular Structure and Function Chapter Assessment Questions _______ is the net movement of particles from an area where there are many particles of the substance to an area where there are fewer particles of the substance. A. Diffusion B. Endocytosis C. Exocytosis D. Equilibrium Chapter 7 Cellular Structure and Function Standardized Test Practice Why are the carrier proteins that move substances across a plasma membrane from a region of higher concentration to a region of lower concentration called pumps? Chapter 7 Cellular Structure and Function Standardized Test Practice A. They require energy to move substances against a concentration gradient. B. They open and close to allow substances to diffuse across the plasma membrane. C. They help with the osmosis of water through the plasma membrane. D. They pump water into the cell, causing the pressure within the cell to increase.