carbohydrates

View mindmap
  • carbohydrates
    • they contain carbon, hydrogen and oxygen
      • monosaccharides.- are the simplest carbohydrates. are a source of energy. they are sweet sugars. glucose is a source of energy
        • are soluble in water and insoluble in non polar substances
          • there are hexose sugars like glucose with 6 carbons, pentose sugars with 5 carbons like ribose. triose with 3 and tetrose with 4
          • glucose can exist as isomers. alpha and beta
      • disaccharides - when two monosaccharides  join by condensation reaction they from glyosidic bonds which form disaccharides. Can be broken by hydrolysis
        • maltose - reducing sugar made from a-glucose  and a-glucose
        • sucrose-non reducing made from a-glucose and fructose
        • lactose- reducing sugars made from b-galactose and a-glucose
        • cellobiose- b-glucose and b-glucose
      • polysaccharides . polymers of monosaccharides bonded together by glyosidic bonds
        • is a store of energy eg when you join lots of glucose you make glycogen in animals and starch in plants
          • polysaccharides are less soluble in water than monosaccharides as what could hydrogen bond are hidden inside the cell. if it was soluble it would affect the water potential of the cell and cause excess water to diffuse in.
          • glycogen and starch are compact in granules, are in chains which can be easily snipped of by hydrolysis when energy is needed
            • some chains are branched and tend to me more compact and offer lots of glucose
        • homopolysaccharide - made of the same type of monomers
        • heteropolysaccharide- made of more than one type of monomer.
    • functions:   source of energy(eg glucose), store of energy (eg starch) and as structural units(cellulose)
      • cellulose. found in plants cell wall, tough insoluble and fibrous.
        • homo polysaccharide made of 1500 beta glucose chains bonded together through condensation reaction to form glyosidic bonds. every other glucose molecule flips 180 degrees for glycosidic bonds to form
          • cellulose chains don't spiral. due to the glucose flips.
        • 60 to 70 cellulose chains make microfibrils. 400 microfibrils make macrofibrils which embed in pectin criss cross for cell walls extra strength.
        • structure and function.    glyosidic bonds allow high tensil strength to support the cell especially when turgid. its difficult to digest. cell wall is permeable. macrofibrils can also be reinforced with other substances for extra support
      • other structural units. bacteria cell walls are called peptidoglycan, made of long polysaccharide chains crosslinked by short peptide chains.            insects and crustacean exoskeleton are made of chitin with an acetylamino group on group 2
    • amylose and amylopectin(which is branched) are starch in plants. they are in spirals held by hydrogen bonds. glycogen is a storage in animals. its not spiralled but is branched with 1-4 and 1-6 glyosidic linkages
  • polysaccharides . polymers of monosaccharides bonded together by glyosidic bonds
    • is a store of energy eg when you join lots of glucose you make glycogen in animals and starch in plants
      • polysaccharides are less soluble in water than monosaccharides as what could hydrogen bond are hidden inside the cell. if it was soluble it would affect the water potential of the cell and cause excess water to diffuse in.
      • glycogen and starch are compact in granules, are in chains which can be easily snipped of by hydrolysis when energy is needed
        • some chains are branched and tend to me more compact and offer lots of glucose
    • homopolysaccharide - made of the same type of monomers
    • heteropolysaccharide- made of more than one type of monomer.

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules resources »