Please enable JavaScript.

Coggle requires JavaScript to display documents.

Lipids - Coggle Diagram

- - - - High ATP levels
        
        kinase inhibited
        
        ACC becomes activated and stimulates malonyl-CoA production.
      - High AMP levels (Low ATP levels)
        
        AMPK inactivates ACC
- - - - efficient
        
        higher caloric yield
      - Economical
        
        Nonpolar so don't bind water
    - - Acetyl CoA
      - NADPH
      - ATP
  - - - Formation of a trans-alpha,beta double bond
        
        Occurs through dehydrogenation by flavoenzyme acyl-CoA dehydrogenase (AD)
      - Hydrogenation of double bond by enoyl-CoA hydratase (EH)
        
        Forms 3-L-hydroxyacyl
      - NAD+ dependent dehydrogenation of beta-hydroxyacyl-CoA to form beta-ketoacyl-CoA
        
        by 3-L-hydrozyacyl-CoA dehydrogenase (HAD)
      - Calpha to Cbeta cleavage in thiolysis reaction with CoA to form acetyl CoA
        
        By thiolase
    - - Unsaturated fatty acids contain only cis double bonds
        
        2 substituents are on the same side of the double bond
        
        Oleic acid
        
        Linoleic acid :
        
        Essential fatty acid
        
        Must be obtained in diet
  - - - Transfer variety of acyl groups
      - Located on mitochondrial membrane
  - - - Exclusively in peroxisomes and glyoxysomes
    - - Acyl-CoA oxidase
      - Peroxisomal enoyl-CoA hydratase adn 3-L-hydoxyacyl-CoA dehydrogenase
      - peroxisomal thiolase
- - - - Enters cytosol in form of citrate via tricarboxylate transport system
      - ATP-citrate lyase catalyses:
        
        Citrate+CoA+ATP -> Acetyl-CoA+oxaloacetate+ADP+Pi
        
        Reverse of citrate synthase reaction
  - - - Mammalian acetyl-CoA carboxylase subject to allosteric and hormonal control
    - - ACC1
        
        occurs in adipose tissue
      - ACC2
        
        Occurs in tissues which oxidise but don't synthesize fatty acids
        
        Regulatory function
  - - - Elongases
        
        Present in mitochondria and endoplasmic reticulum
      - Desaturases
  - - - Glyceroneogenesis
        
        Necessary for times of starvations
      - TAGs broken down into acetyl units
- - - - Glycerol esters like TAG (storage) and DAG
      - Fats - esters of fatty acids
      - Waxes - esters of long chain fatty acids and '' '' alcohols
    - - Phospholipids, glycolipids, lipoproteins
        
        Form lipid bilayers in water
        
        Driven by hydrophobic interactions with hydrocarbon tails which stabilise the bilayer
        
        Consist of phosphate, glycerol and fattty acids
    - - 4 rings in specific orienations eg. testosterone
    - - Diverse biological lipid molecules with many functions
    - - Energy storage and supply
      - Membrane components and coverings
      - Signals, messnegers, cofactors and pigments
    - - Stearate = saturated
        
        Octadecanoate
      - Oleate = unsaturated
        
        Octadececnoate
      - Long aliphatic tail
      - 18 carbons
- - - - Formation occurs in 3 reactions
        
        2 molecules of acetyl-CoA condensed to acetoacetyl-CoA by thiolase
        
        Condensation of acetoacetyl-CoA with 3rd acetyl-CoA to form HMG-CoA
        
        HMG-CoA degraded to acetoacetate and acetyl-CoA by HMG-CoA lyase
    - - becomes brain main fuel source in starvation
  - - - acetoacetate produced faster than it is metabolised - diabetes symptom
- - - - Pancreatic lipase
  - - - Cells lining small intestine
      - Absorb what is produced by lipid digestion
    - - Cytoplasmic protein which increases effective solubility
- - - - By cyclic AMP - regulated lipases
- - - - Package them into lipoproteins
        
        Chylcomicrons
        
        Released into intestinal lymph and drain into large veins
  - - - Transport endogenous (internal) TAGs and cholesterol to tissues
- - - - 1,2-diaglycerol
      - phosphatidic acid
    - - ATP phosphorylates OH group of choline and ethanolamine
      - Resulting phosphoryl group attacks CTP to form CDP derivatives
      - C3-OH group of 1,2-diacylglycerol attacks phosphoryl group of activated CDP-ethanolamine or CDP-choline
    - - Synthesised from phophatidylethanolamine