Final answer:
When 25 monosaccharides are bonded together to form a polysaccharide, 24 water molecules are removed via dehydration reactions that occur as each glycosidic bond is formed.
Step-by-step explanation:
When 25 monosaccharides are bonded together to make a polysaccharide, a dehydration reaction, also known as a condensation reaction, takes place for each bond formed between monosaccharides. In each of these reactions, one water molecule is formed as a byproduct. Therefore, to form the glycosidic bonds necessary to link together 25 monosaccharides, 24 water molecules would be released (since the first monosaccharide does not require a water molecule to be removed for bonding). This is because for each new monosaccharide added, a water molecule is removed.
Thus, for the synthesis of a polysaccharide from monosaccharides, the number of water molecules released is always one less than the number of monosaccharides being linked together.