Skip to main content
Indietro

Cell Membrane Structure and Function

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/21

Termini in questo insieme (21)

  • What is the basic structure of the cell membrane?
    The cell membrane is a phospholipid bilayer that is amphipathic, with a polar hydrophilic phosphate head and a non-polar hydrophobic lipid tail.
  • What does the Fluid Mosaic Model describe?
    It describes the cell membrane as a dynamic structure with lipids and proteins that move laterally, including integral and peripheral proteins.
  • What are integral proteins?
    Integral proteins penetrate the bilayer completely and function as enzymes, receptors, carriers, channels, junctions, and in recognition.
  • What role do cholesterol and other lipids play in the membrane?
    They are embedded in the membrane and help maintain its consistency and fluidity.
  • What does selective permeability of the cell membrane mean?
    The membrane allows some substances to pass while blocking others, controlling the internal environment of the cell.
  • What is simple diffusion?
    Movement of molecules from high to low concentration directly through the membrane without energy or proteins.
  • What is facilitated diffusion?
    Movement of larger or polar molecules across the membrane via integral proteins along their concentration gradient without energy.
  • Define osmosis.
    Osmosis is the diffusion of water across a selectively permeable membrane.
  • What happens in a hypertonic solution?
    Water moves out of the cell, causing it to shrink due to higher solute concentration outside.
  • What happens in a hypotonic solution?
    Water moves into the cell, causing it to swell or burst due to lower solute concentration outside.
  • What is isotonic solution?
    The solute concentration is equal inside and outside the cell, so there is no net water movement.
  • What is active transport?
    Movement of substances against their concentration gradient using transport proteins and energy (ATP).
  • Describe the Na/K pump function.
    It pumps Na+ out and K+ into the cell, maintaining a constant gradient using ATP.
  • What are uniport, symport, and antiport transport types?
    Uniport moves one substance, symport moves two substances together, antiport exchanges one substance in and another out.
  • What is secondary active transport?
    It uses an established concentration gradient to move substances into or out of the cell without direct ATP use.
  • What is endocytosis?
    The process where the cell engulfs substances by wrapping pseudopodia around them to bring them inside.
  • Differentiate phagocytosis, pinocytosis, and receptor-mediated endocytosis.
    Phagocytosis engulfs solids, pinocytosis engulfs liquids, and receptor-mediated endocytosis uses receptors to target specific substances.
  • What is the extracellular matrix (ECM)?
    A non-living component secreted by cells that provides structure and function to tissues, like the mineralized part of bone.
  • What are desmosomes?
    Cell junctions that connect cytoskeletons of adjacent cells with intercellular filaments, providing strength and flexibility.
  • What are tight junctions?
    Plasma membrane proteins of adjacent cells intertwine to form a barrier, preventing fluid movement between cells.
  • What are gap junctions?
    Channels between cells that allow communication and passage of ions or small molecules.