Questions and Answers
Explain why passive transport does not require energy.
No energy is needed because the substances are moving from an area where they have a higher concentration to an area where they have a lower concentration.
What is a main difference between diffusion and facilitated diffusion?
Facilitated diffusion involves movement with the help of other molecules, while diffusion occurs without assistance.
Describe how simple diffusion proceeds. What kind of molecules can move across the membrane by simple diffusion?
Substances that can squeeze between the lipid molecules in the plasma membrane, such as very small, hydrophobic molecules like oxygen and carbon dioxide.
How is water transported across the membrane?
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What are the two types of transport proteins? Describe how they function.
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Explain active transport.
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What is the sodium-potassium pump?
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What is osmosis? What type of transport is it?
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Why do materials move across membranes?
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What is passive transport?
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What is diffusion?
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What is osmosis?
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What are the three types of solutions?
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What is facilitated diffusion?
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Explain active transport.
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What is vesicle transport?
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Study Notes
Passive and Active Transport
- Passive transport allows substances to move from high to low concentration without energy.
- Active transport requires energy to move substances against their concentration gradient.
Types of Transport
- Diffusion: Movement of molecules from an area of higher concentration to lower concentration.
- Facilitated diffusion: Diffusion assisted by transport proteins for specific substances.
Simple Diffusion
- Small, hydrophobic molecules (e.g., oxygen, carbon dioxide) can easily cross the plasma membrane.
- Simple diffusion does not require additional help from other molecules.
Water Transport
- Osmosis: Diffusion of water across a semipermeable membrane; follows the concentration gradient of water.
Transport Proteins
- Two main types include those facilitating movement of oxygen and carbon dioxide across membranes.
Sodium-Potassium Pump
- A critical mechanism that pumps sodium ions out and potassium ions into the cell, essential for maintaining cellular function.
Types of Solutions
- Isotonic: Equal solute concentration, maintaining equilibrium.
- Hypertonic: Higher solute concentration; cells may shrivel and die.
- Hypotonic: Lower solute concentration; cells may burst due to excess water intake.
Vesicle Transport
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Endocytosis: Movement of materials into the cell via vesicles.
- Phagocytosis: Engulfing solid particles.
- Pinocytosis: Engulfing liquid droplets.
- Exocytosis: Process of expelling materials from the cell.
Summary of Osmosis
- A special type of diffusion specifically referring to water molecules crossing a membrane, essential for cellular hydration and nutrient transport.
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Description
This quiz consists of flashcards covering essential concepts in Biology Chapter 3.3, focusing on passive transport, diffusion, and facilitated diffusion. Test your understanding of these topics with key definitions and differences.
