1.3.4 Describe how monosaccharides join to form disaccharides (sucrose, lactose and maltose) and polysaccharides (glycogen and amylose) through condensation reactions forming glycosidic bonds, and how these can be split through hydrolysis reactions.

a disaccharide is formed in a condensation reaction; a water molecule is lost.

sucrose is formed when fructose and glucose join by 1,2-glycosidic bond 

lactose is formed when galactose and glucose join by 1,4-glycosidic bond 

maltose is formed when glucose and glucose join by 1,4-glycosidic bond 

hydrolysis breaks the glycoside bond (a molecule of water is added) which's catalysed by an enzyme.