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Chapter 1: Lipids - Coggle Diagram

- - - - COOH group of fatty and and OH group of glycerol link together to form a ester linkage
    - - TRI- 3 FATTY ACIDS (COOH) group and one glycerol (OH)
    - - C-H bonds new non polar and hence triglycerides are hydrophobic
        
        no associated water molecules stored along triglycerides, hence no extra weight due to water of hydration
        
        triglycerides do not affect the water potential of cells when stored in large amounts
        
        absence of water of hydration fulfils animal's body mass to be kept at minimum to facilitate locomotion ( the ability to move from one place to another)
      - highly reduced molecules
        
        release more water when oxidised during cellular respiration compared to carbohydrates,
        
        water is down as metabolic water (extremely important to desert animals
      - hydrocarbon tails are non polar, allow triglyceride to slide under pressure
      - triglycerides have lower molecular with than water per unit volume
        
        fat aids buoyancy of aquatic animals because they are less dense than water
      - triglycerides have higher proportion of C and H atoms compared to O atoms
        
        upon oxidation, triglycerides release larger amount of energy than carbohydrates
        
        hence fats are efficient energy stores
    - - melting point INCREASES with increasing hydrocrabon chain length
        
        longer chains, more extensive the hydrophobic interactions between the chains, more thermal energy required to break the bonds
      - melting point DECREASES with increasing unsaturation (more double bonds)
        
        kinks formed in double bonds disrupt the close packing of molecules, hence less thermal energy is required to break the less extensive hydrophobic interactions
- - - - 2 fatty acids and 1 glycerol for a ester linkage. 3rd oH group and phosphate group for phosphoester linkage
    - - phospholipids are amphipathic:
        
        form a selectively permeable cell membrane where hydrophillic heads are exposed to aqueous medium while hydrophobic tails are in contact with those of neighbouring molecules but excluded from aqueous medium, forming a effective barrier
        
        form liposome which are used as vesicles for storage and transport of cellular products as well as digestion of waste; also serve as vesicles for drug delivery
        
        phospholipids from micelles used for transport of fats between gut and body tissues
      - hydrophobic interactions exist between fatty acid tails:
        
        integrity od membrane bilayer is maintained due to large number of interactions
        
        individual hydrophobic interactions are weak, permitting lateral movement of phospholipids, accounting for membrane fluidity
    - - 1 glycerol and 2 fatty acids- third OH group is connected to a polar negatively charged phosphate group
    - - amphipathic in water: there are polar (charged hydrophilic head) and hydrophobic hydrocarbon tails
      - three types of lipid aggregates can form:
        
        micelle: small, spherical droplet consistingf of a phospholipid monolayer, with the hydrophillic phosphate head on the outside in contact with the aqueous envrionemtn and the hydrocarbon tails restricted to water free interior of miscelle
        
        2.Bilayer : two lipid monolayers combine to form a two dimensional sheet
        
        hydrophillic heads are exposed to the polar exterior while hydrophobic tails are in contact with those of neighbouring molecules but excluded from water in non polar interior of bilayer
        
        liposome/vesicle: lipid biller folds back on itself to form a hollow sphere. by forming vesicles, bilayer sheets avoid exposing their hydrophobic edge regions, achieving maximal stability in their aqueous environemnt