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CH10 Lipids, CH11 Biological Membranes and Transport - Coggle Diagram

- - - - high m.p.
  - - - 1 double bonds
        
        C9
    - - more than 1 double bonds
        
        C9.12.15
        
        通常非共軛
  - - - first carbon of the alkene in
        relationship to the carbonyl carbon
    - - first carbon of the alkene in
        relationship to the terminal methyl
  - - - solubility⇩, chain length⇧
    - - m.p.⇩, chain length⇩
      - m.p.⇩, double bonds⇧
  - - - cis configuration, kink the chain
- - - - thromboxanes (formation of blood clots)
      - leukotrienes (smooth muscle contraction in lungs)
      - prostaglandins (inflammation and fever)
- - - - a long-chain amino alcohol sphingosine.
      - A fatty acid is joined to sphingosine via an amide linkage, rather than an ester linkage as usually seen in lipids
      - e backbone of sphingolipids is NOT glycerol
      - sugar-containing glycosphingolipids are found
        largely in the outer face of plasma membranes
      - Ceramide (sphingosine + amide-linked fatty acid) + phosphocholine attached to the alcohol
        
        Sphingomyelin is abundant in myelin sheath thatsurrounds some nerve cells in animals.
      - Blood Groups
        
        determind by head group
        
        expression by specific glycosyltransferases
        
        transfers galactose
        
        B blood group
        
        transfer N-acetylgalactosamine
        
        A blood group
        
        no active
        
        O antigen
    - - abundant in plant chloroplasts but almost
        absent in animals
  - - - Vinyl ether analog of phosphatidylethanolamine
      - Common in vertebrate heart tissue, also found in some protozoa and anaerobic bacteria
      - Function is not well understood
    - - Acetic acid has esterified position C2
      - First signaling lipid to be identified
      - Aliphatic ether analog of phosphatidylcholine
      - Stimulates aggregation of blood platelets
  - - - Two fatty acids form ester linkages with the first and
        second hydroxyl groups of L-glycerol-3-phosphate
      - e phosphate group is charged at physiological pH
      - primary constituents of cell membranes
      - The highly polar phosphate group may be further esterified by an
        alcohol ▶head groups.
      - Unsaturated fatty acids are commonly found connected to C2 of
        glycerol-3-phosphate
    - - A polar head group is connected to sphingosine by a phosphodiester linkage
      - e backbone of sphingolipids is NOT glycerol
      - sugar-containing glycosphingolipids are found
        largely in the outer face of plasma membranes
    - - Phospholipids are degraded by
        phospholipases A−D
      - Gangliosides are degraded via a
        series of enzymatic cleavages
        
        Dysfunction in Ganglioside Recycling
        Leads to a Variety of Medical Disorders
- - - - body fat
- - - - oxidized derivatives of sterols
      - have the sterol nucleus but lack the alkyl chain found in cholesterol
      - synthesized from cholesterol in gonads and adrenal gland
      - more polar than cholesterol
      - male and female sex hormones
  - - - thicken the plasma membrane
      - modulate fluidity and permeability
      - Mammals obtain cholesterol from food or synthesize
        it de novo in the liver
      - Cholesterol, bound to proteins, is transported to
        tissues via blood vessels
- - - - membrane bilayer
        
        Forms when lipids with polar head groups and more than one lipid tail are in aqueous solution
        • phospholipids
        • sphingolipids
        
        Hydrophilic head groups interact with water on both sides, Hydrophobic fatty acid tails are packed inside
        
        two leaflets (e.g., layers) of lipid monolayers
      - vesicle (liposome)
        
        Synthetic vesicle membranes can be made in vitro and can contain artificially inserted proteins
        
        central aqueous cavity can enclose dissolved molecules
        
        bilayers will spontaneously seal into spherical vesicles in a concentration-dependent manner
        
        useful artificial carriers of molecules (e.g., drugs)
      - micelle
        
        composed of few dozen to thousand lipid molecules
        
        Aggregation of individual lipids into micelles is concentration dependent
        
        amphipathic
  - - - except archaebacteria: monolayer
  - - - :star: monolayer in some archaea
  - - - integral membrane proteins
        
        Removed by detergents that disrupt the membrane
        
        Selectively Placed Nonpolar Amino Acids Within the Membrane
        
        Hydropathy Plots Can Predict Transmembrane Domains
        
        Span the entire membrane
        
        Purified integral membrane proteins still have phospholipids associated with them
      - Amphitrophic and GPI-linked proteins
        
        conditionally attached to the membrane by covalent interaction with lipids or carbohydrates attached to lipids
        
        GPI anchored, only found on outer face
        
        reversibly removed, found both membrane & cytosol
      - Peripheral (non-GPI linked) membrane proteins
        
        Relatively loosely associated with membrane
        
        Removed by disrupting ionic interactions either with high salt or change in pH
    - - N-myristoyl group
      - farnesyl (or geranylgeranyl) group
        
        farnesylation
        
        protein can be targeted to inner leaflet
        
        primary sequence: Caax
      - palmitoyl group
      - GPI anchor
        
        outer face
        
        direct protein to correct cellular location
- - - - 上下移動慢
    - - floppase外翻轉酶
        
        內到外
      - scramblase雙向翻轉酶
        
        順濃度梯度，不耗能
      - flippase翻轉酶
        
        外到內
    - - 橫向移動快
  - - - photobleaching
      - measure recovery
      - label outside of cell