Isotonic, Hypotonic, and Hypertonic Solutions
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the hydrophilic regions of proteins in the membrane?

  • To expose themselves to water (correct)
  • To flip-flop transversely across the membrane
  • To facilitate lateral movement of proteins
  • To interact with the hydrophobic tails of phospholipids
  • Which of the following is NOT a function of the cell membrane?

  • Regulating cell growth (correct)
  • Maintaining ion concentrations of various substances
  • Controlling incoming and outgoing substances
  • Protecting the cell
  • What is the average frequency of a phospholipid molecule flip-flopping across the membrane?

  • Once per month (correct)
  • Once per year
  • Once per minute
  • Once per second
  • What is the term for the ability of the cell membrane to allow certain molecules to pass through while keeping others out?

    <p>Selective permeability</p> Signup and view all the answers

    What is the main component of the cell membrane that helps to maintain its fluidity?

    <p>Phospholipids</p> Signup and view all the answers

    What is the primary function of the plasma membrane?

    <p>To separate the living cell from its surroundings</p> Signup and view all the answers

    What is the term for the movement of proteins and lipids within the membrane?

    <p>Lateral movement</p> Signup and view all the answers

    What is the major role of the cell membrane in maintaining homeostasis?

    <p>All of the above</p> Signup and view all the answers

    What is the term used to describe the ability of the plasma membrane to allow some substances to cross it more easily than others?

    <p>Selective permeability</p> Signup and view all the answers

    What is the most abundant lipid in the plasma membrane?

    <p>Phospholipid</p> Signup and view all the answers

    What is the model that describes the structure of the cell membrane?

    <p>Fluid Mosaic Model</p> Signup and view all the answers

    What is the term used to describe the structure of phospholipids?

    <p>Amphipathic</p> Signup and view all the answers

    What is the name of the model that describes the plasma membrane as a fluid structure with a mosaic of proteins embedded in it?

    <p>Fluid mosaic model</p> Signup and view all the answers

    Who proposed the sandwich model of the plasma membrane?

    <p>Hugh Davson and James Danielli</p> Signup and view all the answers

    What is the main criticism of the sandwich model of the plasma membrane?

    <p>It does not account for the placement of membrane proteins</p> Signup and view all the answers

    In a hypotonic solution, what is the concentration of solutes compared to inside the cell?

    <p>Lower</p> Signup and view all the answers

    What is the function of the integral proteins in the plasma membrane?

    <p>To regulate the movement of substances into and out of the cell</p> Signup and view all the answers

    What happens to a cell in a hypotonic solution?

    <p>It swells and bursts open</p> Signup and view all the answers

    What is the direction of water movement in a hypertonic solution?

    <p>From inside the cell to the solution</p> Signup and view all the answers

    What is the result of a cell in an isotonic solution?

    <p>It stays the same</p> Signup and view all the answers

    What is the main reason for water movement in osmosis?

    <p>Solute concentration difference</p> Signup and view all the answers

    What is the term for the bursting of a cell due to excessive water uptake?

    <p>Cytolysis</p> Signup and view all the answers

    What happens to the cell membrane in a hypertonic solution?

    <p>It becomes less permeable</p> Signup and view all the answers

    What is the main difference between a hypotonic and a hypertonic solution?

    <p>Solute concentration</p> Signup and view all the answers

    What is the primary characteristic of passive transport?

    <p>It does not use energy from the cell.</p> Signup and view all the answers

    What is the net direction of solute movement in diffusion through a membrane?

    <p>From an area of high concentration to an area of low concentration.</p> Signup and view all the answers

    What is the purpose of proteins in facilitated diffusion?

    <p>To carry polar molecules or ions across the membrane.</p> Signup and view all the answers

    What is the state of the molecules in a system at equilibrium?

    <p>They are evenly spaced, but still moving randomly.</p> Signup and view all the answers

    What is the primary difference between simple diffusion and facilitated diffusion?

    <p>The use of proteins to facilitate molecule movement.</p> Signup and view all the answers

    What is the result of diffusion continuing until all molecules are evenly spaced?

    <p>The molecules will continue to move, but will be evenly spaced.</p> Signup and view all the answers

    What is the characteristic of molecules that allows them to move from an area of high concentration to an area of low concentration?

    <p>Their kinetic energy.</p> Signup and view all the answers

    What is the term for the movement of molecules from an area of high concentration to an area of low concentration?

    <p>Diffusion.</p> Signup and view all the answers

    What is the primary driving force for osmosis?

    <p>The concentration gradient of water across a membrane</p> Signup and view all the answers

    In a hypotonic solution, what happens to the cell?

    <p>The cell will swell due to water gain</p> Signup and view all the answers

    What is the term for a solution that has the same concentration of solutes as the cell?

    <p>Isotonic solution</p> Signup and view all the answers

    What happens to the cell in a hypertonic solution?

    <p>The cell will shrink due to water loss</p> Signup and view all the answers

    What is the role of solutes in osmosis?

    <p>Solutes attract water molecules, causing them to move towards areas of high solute concentration</p> Signup and view all the answers

    What is the term for the movement of water across a selectively permeable membrane?

    <p>Osmosis</p> Signup and view all the answers

    What is the result of a cell in an isotonic solution?

    <p>The cell will remain the same size</p> Signup and view all the answers

    What is the term for the state of equal water movement in both directions across a membrane?

    <p>Dynamic equilibrium</p> Signup and view all the answers

    Study Notes

    Cell Equilibrium and Osmosis

    • In a state of equilibrium, water flows in both directions across the cell membrane, and solute and water concentrations are equal inside and outside the cell.
    • Hypotonic solution: has a lower concentration of solutes and a higher concentration of water than inside the cell, resulting in water moving into the cell, causing it to swell and potentially burst (cytolysis).
    • Hypertonic solution: has a higher concentration of solutes and a lower concentration of water than inside the cell, resulting in water moving out of the cell, causing it to shrink (plasmolysis).

    Cell Membrane Structure and Function

    • The plasma membrane is a selective barrier between the cell and its surroundings, controlling the movement of substances in and out of the cell.
    • Phospholipids are the most abundant lipid in the plasma membrane, and are amphipathic molecules with hydrophobic and hydrophilic regions.
    • The fluid mosaic model describes the plasma membrane as a fluid structure with embedded proteins, allowing for selective permeability.

    Functions of Membranes

    • Protect the cell
    • Control the movement of substances in and out of the cell
    • Maintain ion concentrations and homeostasis
    • Selectively permeable, allowing some molecules to pass through while keeping others out

    Phospholipid Bilayer and Fluidity

    • Phospholipids in the plasma membrane can move laterally within the bilayer
    • Rarely do molecules flip-flop transversely across the membrane
    • The fluidity of the membrane allows for the lateral movement of lipids and proteins

    Transport Across Membranes

    Passive Transport

    • Diffusion: the random movement of particles from an area of high concentration to an area of low concentration
    • Osmosis: the diffusion of water across a selectively permeable membrane, moving from high to low water concentration
    • Facilitated diffusion: the use of proteins to carry polar molecules or ions across the membrane

    Active Transport

    • Requires energy from the cell
    • Examples include protein pumps, endocytosis, and exocytosis

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the concept of equilibrium in cells, and the movement of water in and out of cells in different solutions. It includes isotonic, hypotonic, and hypertonic solutions.

    More Like This

    Osmosis: Movement of Water Molecules
    8 questions
    Biology: Diffusion and Osmosis
    13 questions
    Osmosis Experiment
    38 questions

    Osmosis Experiment

    CheerfulHydrangea avatar
    CheerfulHydrangea
    Use Quizgecko on...
    Browser
    Browser