1.12 i) Know the difference between monosaccharides, disaccharides and polysaccharides, including glycogen and starch (amylose and amylopectin). ii) Be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and storing energy

monosaccharide- single sugar unit (CH2O)n - n is number of carbon atoms

• 3-7 carbon atoms , most commonly 6 (hexose sugars) e.g. glucose galactose, fructose
• rapid source of energy- little change required for use in cellular respiration

disaccharide- two single units combined in a condensation reaction

glycosidic bond; forms between two sugar units

polysaccharide- long straight or branched chains of sugar units (3+)

• starch- plants  (amylose + amylopectin) 
• glycogen- polymer of glucose- side branches- insoluble- animals,, fungi, bacteria
• energy store 

condensation reactions: formation of complex molecules (-water)
hydrolysis reactions: splits the molecule (+water)

amylose 
straight chain 200-500 glucose molecules. 1,4 glycosidic bonds between adjacent glucose molecules resultant in spiral shape.
amylopectin 
side branches. 1,6 glycosidic link holding side branch to main chain.

structures related to functions. 
side branches allow molecules to be easily hydrolyzed.
low solubility in water means they do no affect the concentration of water in the cytoplasm.

carbon atoms are numbered from 1 clockwise from the oxygen. e.g maltose has a 1,4 glycosidic bond because it forms between carbon 1 on one molecule, 4 on the other.

dietary fibre - cellulose- indigestible in the human gut - movement of material through digestive tract.