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AP® biology unit 2 Flashcards

AP® biology unit 2
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  • What is the primary function of the cell membrane?
    To regulate the movement of substances in and out of the cell.
  • Describe the fluid mosaic model.
    A model that describes the cell membrane as a flexible layer made of lipid molecules interspersed with proteins.
  • What role do phospholipids play in the cell membrane?
    They form a bilayer that acts as a barrier to most water-soluble substances.
  • How do proteins assist in cell membrane function?
    They help transport substances, act as enzymes, or serve as receptors.
  • What is the difference between passive and active transport?
    Passive transport does not require energy, while active transport does.
  • What is osmosis?
    The diffusion of water across a selectively permeable membrane.
  • Define facilitated diffusion.
    The process of spontaneous passive transport of molecules across a biological membrane via specific transmembrane proteins.
  • What is the role of cholesterol in the cell membrane?
    It helps maintain fluidity and stability of the membrane.
  • Explain the term 'selectively permeable'.
    A property of cell membranes that allows some substances to pass through while others cannot.
  • What is the function of glycoproteins in the cell membrane?
    They play a role in cell recognition and signaling.
  • How does temperature affect membrane fluidity?
    Higher temperatures increase fluidity, while lower temperatures decrease it.
  • What is endocytosis?
    The process by which cells take in substances by engulfing them in a vesicle.
  • Describe the process of exocytosis.
    The release of substances from a cell when a vesicle fuses with the cell membrane.
  • What is the role of aquaporins?
    They facilitate the transport of water across cell membranes.
  • What is the significance of the sodium-potassium pump?
    It helps maintain the electrochemical gradient across the cell membrane.
  • How do ion channels function?
    They allow specific ions to pass through the membrane in response to a signal.
  • What is the difference between hypertonic and hypotonic solutions?
    Hypertonic solutions have a higher solute concentration, while hypotonic solutions have a lower solute concentration.
  • What is the role of the cytoskeleton in cell membrane function?
    It provides structural support and helps maintain the shape of the cell.
  • What is the function of carrier proteins?
    They transport specific substances across the cell membrane.
  • What is the role of ATP in active transport?
    ATP provides the energy needed to move substances against their concentration gradient.