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Introduction to Membrane Transport definitions Flashcards

Introduction to Membrane Transport definitions
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  • Membrane Transport
    Movement of molecules across a cell membrane, either passively without energy or actively with energy, through selective permeability, allowing specific molecules to pass while blocking others.
  • Biological Membranes
    Semi-permeable barriers that selectively allow certain molecules to pass while blocking others, crucial for maintaining cellular homeostasis and facilitating specific transport processes.
  • Semi Permeable
    A membrane that allows certain molecules to pass through while blocking others, based on size, charge, or solubility, ensuring selective permeability.
  • Selectively Permeable
    A membrane property allowing selective passage of certain molecules while blocking others, based on size, charge, or solubility.
  • Diffusion
    Movement of molecules from an area of high concentration to an area of low concentration without the need for energy or transport proteins.
  • Sodium Ion
    A positively charged ion that cannot freely cross the cell membrane due to its charge and size, requiring specific transport proteins to move across biological membranes.
  • Oxygen Molecule
    A diatomic molecule essential for respiration, small and nonpolar, easily diffuses across cell membranes without the need for transport proteins.
  • Lipid Bilayer
    A double-layered structure of phospholipids forming the core of cell membranes, with hydrophobic tails inward and hydrophilic heads outward, regulating molecule passage selectively.
  • Phospholipids
    Amphipathic molecules with hydrophilic heads and hydrophobic tails, forming the bilayer of cell membranes, crucial for selective permeability and membrane fluidity.
  • Hydrophobic
    Repels water and does not mix with it, often due to nonpolar characteristics, making it unable to interact with polar molecules like water.
  • Hydrophilic
    Attracted to water, these molecules or substances can form hydrogen bonds with water, allowing them to dissolve or interact easily in aqueous environments.
  • Polar
    Molecules with uneven distribution of charges, resulting in partial positive and negative regions, making them hydrophilic and less likely to pass through the hydrophobic lipid bilayer of cell membranes.
  • Carbon Dioxide
    A small, nonpolar gas molecule that easily diffuses through cell membranes without the need for transport proteins.
  • Endocytosis
    The process by which cells engulf external substances, forming vesicles to internalize them, often for nutrient uptake or defense.
  • Phagocytosis
    A process where a cell engulfs large particles or microorganisms by extending its membrane around them, forming a vesicle that is then internalized.