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chapter 3

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Terms in this set (26)

  • Phospholipid Bilayer
    A double layer of fat molecules with hydrophilic heads facing water and hydrophobic tails hidden inside, forming the basic structure of the plasma membrane.
  • Role of Cholesterol in the Membrane
    Acts like glue or stiffeners inside the phospholipid bilayer to keep the membrane stable and flexible.
  • Integral Membrane Proteins
    Proteins that span the entire membrane, forming tunnels or channels for molecules to pass through.
  • Peripheral Membrane Proteins
    Proteins that sit on the surface of the membrane like sticky notes, involved in signaling or structural support.
  • Six Main Functions of Membrane Proteins
    Anchors, Identifiers, Enzymes, Receptors, Carriers, and Channels.
  • Glycocalyx
    A sugary coating on the cell surface that acts as an ID card, lubricant, and sticking agent.
  • Microfilaments (Actin)
    Thin protein fibers that shape the cell and aid in movement and muscle contraction.
  • Intermediate Filaments
    Structural protein cables that provide internal strength to the cell.
  • Microtubules
    Protein tubes that serve as tracks for moving organelles and help split chromosomes during cell division.
  • Cilia vs. Flagella
    Cilia are tiny oars that move fluid across the cell surface; flagella are long tails that propel the entire cell.
  • Mitochondria Structure
    Double membrane organelle with inner folds called cristae and fluid matrix inside, producing ATP.
  • DNA Packaging in the Nucleus
    DNA wraps around histones forming chromatin when resting and condenses into chromosomes during cell division.
  • Central Dogma of Molecular Biology
    DNA is transcribed to RNA, which is translated into protein.
  • Selective Permeability of the Membrane
    The membrane allows small, lipid-soluble molecules to pass easily but blocks large or charged molecules without assistance.
  • Passive Transport
    Movement of molecules down their concentration gradient without using energy (ATP).
  • Active Transport
    Movement of molecules against their concentration gradient using energy (ATP).
  • Factors Increasing Diffusion Rate
    Shorter distance, smaller molecules, higher temperature, steeper concentration gradient, and electrical attraction.
  • Osmosis
    Water movement toward areas with higher solute concentration; 'water follows salt/solute.'
  • Isotonic Solution
    Solution where water moves in and out of the cell equally, keeping the cell normal.
  • Hypotonic Solution
    Solution with lower solute concentration outside the cell, causing water to rush in and the cell to swell or burst.
  • Hypertonic Solution
    Solution with higher solute concentration outside the cell, causing water to leave and the cell to shrink.
  • Facilitated Diffusion
    Passive transport where molecules move downhill through carrier proteins, which can become saturated.
  • Sodium-Potassium Pump
    Primary active transport that uses 1 ATP to pump 3 Na\(^{+}\) out and 2 K\(^{+}\) in.
  • Secondary Active Transport
    Transport where one molecule moves downhill and another moves uphill, indirectly using ATP.
  • Endocytosis Types
    Receptor-mediated (specific ligand binding), pinocytosis (cell drinking), and phagocytosis (cell eating solids).
  • Exocytosis
    Process where vesicles fuse with the plasma membrane to release contents outside the cell.