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Concentration Gradients and Diffusion quiz #2 Flashcards

Concentration Gradients and Diffusion quiz #2
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  • What is a concentration gradient?
    A concentration gradient is the difference in concentration of a substance between two areas, where molecules move from high to low concentration naturally.
  • Which cell size is the most efficient at exchanging materials with the environment?
    Smaller cells are more efficient at exchanging materials with the environment due to their higher surface area-to-volume ratio.
  • Which of the following would not diffuse through the plasma membrane by means of simple diffusion? A) Oxygen B) Glucose C) Carbon dioxide D) Water
    B) Glucose would not diffuse through the plasma membrane by means of simple diffusion because it is a larger molecule.
  • Which of the following cube-shaped cells would be most efficient in removing waste by diffusion? A) 1x1x1 B) 2x2x2 C) 3x3x3 D) 4x4x4
    A) 1x1x1 cube-shaped cell would be most efficient in removing waste by diffusion due to its higher surface area-to-volume ratio.
  • The rate of diffusion of a molecule into a cell is affected by which of the following factors? A) Temperature B) Concentration gradient C) Surface area D) All of the above
    D) All of the above; temperature, concentration gradient, and surface area affect the rate of diffusion.
  • Which would increase the rate of diffusion across a cell membrane?
    Increasing the temperature or the concentration gradient would increase the rate of diffusion across a cell membrane.
  • What is the relationship between the cell size and the cell nutrient absorption rate?
    Smaller cells have a higher nutrient absorption rate due to their larger surface area-to-volume ratio.
  • Which of the following impacts the rate of diffusion into a cell? A) Membrane thickness B) Concentration gradient C) Temperature D) All of the above
    D) All of the above; membrane thickness, concentration gradient, and temperature impact the rate of diffusion.
  • What is diffusion?
    Diffusion is the net movement of a substance from an area of high concentration to an area of low concentration.
  • Why does diffusion not require energy?
    Diffusion does not require energy because molecules naturally move down their concentration gradient from high to low concentration.
  • What is a concentration gradient in the context of cellular biology?
    A concentration gradient is the difference in the concentration of a substance between two areas.
  • Does diffusion require energy input from the cell? Why or why not?
    No, diffusion does not require energy because molecules move naturally down their concentration gradient.
  • What is the net movement of molecules during diffusion?
    The net movement is from an area of high concentration to an area of low concentration.
  • Why is energy required to move molecules from low to high concentration?
    Energy is required because this movement is against the natural tendency of molecules and goes up the concentration gradient.
  • How does the concept of concentration gradients relate to homeostasis?
    Cells use concentration gradients to regulate the movement of substances, helping maintain internal balance or homeostasis.
  • Describe what happens to dye molecules when a drop of dye is added to water.
    The dye molecules move from the area of high concentration (where the drop was added) to areas of lower concentration until evenly distributed.
  • Why do molecules have a natural tendency to move down their concentration gradient?
    Because moving down the gradient increases entropy and does not require energy input.
  • How does diffusion contribute to metabolic pathways in cells?
    Diffusion allows for the passive movement of substances needed for metabolic reactions within the cell.
  • What is required for a molecule to move up its concentration gradient?
    An input of energy is required, often in the form of ATP.
  • How does the analogy of a biker going uphill relate to active transport?
    Like a biker pedaling uphill, moving molecules against their concentration gradient requires energy.
  • Why is understanding concentration gradients important for studying cell biology?
    It is essential for understanding how substances move in and out of cells and how cells maintain homeostasis.