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CH5 - Membrane Structure, Synthesis and Transport - Coggle Diagram

- - - - Transmembrane Protein - embedded to the hydrophobic part of membrane
      - Lipids Anchored Proteins - Amino acid covalently bonded to lipids
    - - Bound to integral membrane proteins projecting out
      - bond to phospholipids heads
  - - - occurs in cytosolic leaflet of smooth ER
      - cytosol and endomembrane
        system work together for synthesis
        
        transported by:
        
        lateral fusion to Nuclear envelope
        
        via vesicles to eg Golgi, lysosomes
        
        lipid exchange protein (from one membrane to another)
    - - most transported via vesicles to other membranes from ER
  - - - non-spontaneous
        
        Flippase - needs ATP
      - Spontaneous
        
        Rotational
        
        Lateral movement
    - - Composed differently:
        
        higher cholesterol
        
        Plays a part in endocytosis/cell signalling
        
        unique set of membrane proteins
    - - Length - shorter Acyl tail inc fluidity
      - Double Bonds - makes it more fluid
      - Cholesterol - higher cholesterol = stiff
        
        varies with temperature
        
        higher temp = more stiff
        
        lower temp = less stiff
- - - - A H+/sucrose symporter uses the H+ gradient to transport sucrose against a concentration gradient into the cell.
    - - Endocytosis
        
        Plasma membrane invaginates (folds inward) to form a vesicle that brings substances into the cell
        
        Receptor-mediated endocytosis
        
        a process by which cells absorb metabolites, hormones, proteins
        
        some cases viruses
        
        Pinocytosis
        
        a process by which liquid droplets are ingested by living cells.
        
        Phagocytosis
        
        ingest solid particles into the cell.
      - Exocytosis
        
        Material inside the cell packaged into vesicles and excreted into the extracellular medium.
  - - - Channels - open passageway for the direct diffusion
        
        e.g. Aquaporins
        
        Most are gated
        (ligands)
      - Transporters
        
        carriers
        
        Conformational change transports solute across membrane.
        
        transport of organic molecules, such as sugars,
        
        Symporter - Two or more ions or molecules transported in same direction
        
        Antiporter - Two or more ions or molecules transported in opposite directions
        
        Uniporter - Single molecule or ion
    - - Isotonic Solution - Equal water and solute concentrations on either side of the membrane
        
        Cells maintain shape size
      - Hypotonic Solution
        
        Solute concentration is lower (and water concentration higher) on one side of the membrane
        
        Osmotic Lysis – swelling and bursting of a cell in a hypotonic solution
      - Hypertonic solution - Higher solute concentration and water concentration low) on one side of membrane
        
        Crenation – shrinkage of a cell in a hypertonic solution.
      - When the solute cant move osmosis causes cell to shrink
      - Using vacuoles to remove excess water maintains a constant cell volume
  - - - Transmembrane gradient
        
        Concentration of a solute is higher on one side of a membrane than the other
      - Ion electrochemical gradient
        
        Both an electrical gradient and chemical gradient