Consist of long chains of monosaccharides Usually polymers of glucose monomers Joined by glycosidic linkages (yields May be simple linear molecules But some are branched (more complex) &/or have cross-links between chains Different structures & functions depend on how the monomers are linked together Starch: Plants Branched & unbranched forms See as large granules within chloroplasts Glycogen: Animals Highly branched See as granules (smaller than starch) in cytosol Lots in liver & muscle cells Starch and glycogen are both alpha-glucose polysaccharides Cellulose: Beta-glucose polysaccharide O-H orientation makes it hard to digest Plant cell walls Hydrogen-bonding between chains strong microfibrils Most abundant organic compound on earth Animals can only digest cellulose if they have symbiotic bacteria in their guts Cows Termites Chitin: Fungal cell walls and insect exoskeletons Monomers have an extra nitrogen-containing side-chain added to glucose Poorly soluble in water however soluble in non-polar solvents. Grouped dependent on solubility. The different groups are: Fats & oils for energy storage, insulation and cushioning – Phospholipids animal cell membrane structure –
Consist of long chains of monosaccharides Usually polymers of glucose monomers Joined by glycosidic linkages (yields May be simple linear molecules But some are branched (more complex) &/or have cross-links between chains Different structures & functions depend on how the monomers are linked together Starch: Plants Branched & unbranched forms See as large granules within chloroplasts Glycogen: Animals Highly branched See as granules (smaller than starch) in cytosol Lots in liver & muscle cells Starch and glycogen are both alpha-glucose polysaccharides Cellulose: Beta-glucose polysaccharide O-H orientation makes it hard to digest Plant cell walls Hydrogen-bonding between chains strong microfibrils Most abundant organic compound on earth Animals can only digest cellulose if they have symbiotic bacteria in their guts Cows Termites Chitin: Fungal cell walls and insect exoskeletons Monomers have an extra nitrogen-containing side-chain added to glucose Poorly soluble in water however soluble in non-polar solvents. Grouped dependent on solubility. The different groups are: Fats & oils – for energy storage, insulation and cushioning Phospholipids – animal cell membrane structure
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