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Cell Transport And Diffusion - Coggle Diagram

- - - - Exocytosis
        
        The movement of large molecules out of the cells through the fusion of vesicles to the cell membrane
      - Endocytosis
        
        The movement of large molecules into cells through vesicle formation
        
        The fluid nature of the cell membrane allows vesicle formation
        
        a tiny, fluid-filled sac enclosed by a membrane, acting as a cellular "delivery truck" or storage unit, vital for moving substances (like proteins, nutrients, waste) within cells, between cells, or out of the cell, forming from organelles like the ER or Golgi
  - - - Facilitated Diffusion : Diffusion that takes place through carrier proteins and channels. The protein lined pores make this possible.
      - Osmosis
        
        Specialised form of diffusion of solvent molecules (in cells, free water molecules)
        
        Net movement of particles from an area of high to low water potential
        
        Down the water potential gradient through a partially permeable membrane
        
        The partially permeable nature allows the solutes disolved in the water to accumulate on either side of the membrane
      - Diffusion
        
        Net, random movement of particles of a fluid from an area of high concentration to an area of low concentration
        
        Cell membranes are not a barrier to the diffusion of small particles
- - - - Particles that require this:
        Charged : strong positive or negative
        Large molecules
      - They require channel and carrier proteins embedded in the cell membrane and a concentration gradient
        
        Each type of channel protein, allows only one type of molecule to pass through, depends on molecule shape and charge
        
        GATED CHANNELS :
        Some channels only open if a specific type of molecules is present
        If there is an electrical charge present across the membrane such as during a the passage of nerve impulses through neurone
        
        Carrier protein embedded in the cell membrane has a specific binding site that only fits a certain target molecule
        
        Conformational Change :Upon binding, the protein changes shape often triggered by energy or a gradient
        
        Translocation: This shape change shifts the binding site from one side of the membrane to the other.
        
        The molecule is released on the other side and the protein regains its shape
  - - - Therefore the water molecules that are not associated with solutes
    - - There osomotic concentrations is the measure of those dissolved substances that have an osmotic effect
        
        Hypotonic
        
        The osmotic concentration of the solutes in the solution is LOWER than in the cytoplasm of the cell
        
        Animal cell bursts
        
        Hypertonic
        
        The osmotic concentration of the solutes in the solution is HIGHER than in the cytoplasm of the cell
        
        Animal cell shrivels
        
        Isotonic
        
        The osmotic concentration of solutes in the solution is the SAME as in the cytoplasm of the cell
      - Plant Cells on the basis of Osmostic effect
        
        In plant cells, the cellulose cell walls prevent cells bursting
        
        Water will enter the cell through osmosis in a hypotonic solution
        
        The cytoplasm swells and presses on the cell wall, hydrostatic pressure
        
        PRESSURE POTENTIAL: Inward pressure of the cell wall on the cytoplasm increases until it cancels out the tendency for water molecules to enter in
        
        TURGOUR
        
        When the osmotic force that drives the water in is equal to the pressure potential driving it out, the plant cell is in a rigid state
      - Plant cells in hypertonic Solutions
        
        Water moves out of the cell and turgor is lost if placed in slightly hypertonic
        
        The cell membrane pulls away from the cell wall as the protoplasm shrinks. This is called Incipient plasmolysis
        
        Measured when 50% of the cells are plasmolyse and 50% are not
        
        the point at which so much water has moved out of the cell by osmosis , turgor is lost and the cell membrane pulls away from the cell wall
        
        If placed in entirely hypertonic solution
        
        Water moves out and the cell becomes plasmolysed
        
        When so much water leaves the cell via osmosis the vacuole is reduced and the cell membrane pull away and the protoplasm shrinks
  - - - Diffusion is a passive process because it doesn't require energy from ATP but still needs KE
    - - This random motion means they spread out and eventually reach uniform motion
        
        Molecules don't stop after uniform motion but keep moving.
        They just don't cause a change in concentration as all particles move in all directions
- - - - Hydrolysis of ATP: breaking one bond and forming two bonds
      - Provides energy to move carrier systems, transport substances and return the system to normal
  - - - These substances will move out again through open channels down the concentration or electrochemical gradient
  - - - Sodium pump actively moves potassium in and moves sodium out
        
        Each nerve impulse depends on the influx of sodium ions through the axon membrane and then effectively pumped out so another impulse and pass through
  - - - Takes place in living and respiring cells
      - Rate of active transport depends on the oxygen concentration and temperature
      - Cells that carry loads of ATP are known to contain lots of mitochondria - site of aerobic respiration and ATP production
      - Poison that stop respiration or prevent ATPase from working also stop ATP production
        
        Cyanide prevents the synthesis of ATP during cellular respiration now due to to absence of ATP stops active transport but if ATP is added again artificially it restarts
- - - - To pocket off and form an internal vesicle (endosome) to bring them inside the cell
  - - - Proteins bud off in their own vesicles
        
        Merge with their Golgi apparatus where they are further processed
        
        Bud off the Golgi apparatus into further vesicles
        
        Membranes of the vesicles merge with the membrane of the cell and the contents are released outside of the cell
        
        The motor proteins use ATP that actively push the vesicles towards the membranes