Task

Glucose is the most abundant monosaccharide. It gives reactions typical both of aldehydes and of polyhydric alcohols, and in solution exists mainly in cyclic forms. Fermentation of glucose yields various substances. 1) Show the open-chain (aldehyde) form of glucose and the cyclic α- and β-forms with structural formulas (explain in words which atoms close the ring and how α and β differ); mark the functional groups. 2) Write reactions proving that glucose is an aldehyde and a polyhydric alcohol: silver mirror, copper(II) hydroxide in the cold and on heating, reduction with hydrogen; state the visible sign of each. 3) Write the equations for alcoholic, lactic-acid and butyric-acid fermentation of glucose and name the products. No calculations are required: for each part give the reaction equations (with structural formulas), conditions, names of substances and the necessary explanations.