Final answer:
The Beta-1,4-glycosidic bond found in cellulose is a type of polysaccharide bond that cannot be digested by mammalian enzymes. This bond is distinct from the digestible alpha-glycosidic bonds found in other polysaccharides like amylose and is responsible for making cellulose indigestible, providing fiber that aids digestion without nutritional value.
Step-by-step explanation:
The polysaccharide bond that cannot be broken by mammalian enzymes that normally digest polysaccharides is the Beta-1,4-glycosidic bond.
Polysaccharides are long carbohydrate molecules composed of multiple monosaccharide units linked by glycosidic bonds. The mammalian digestive system produces a variety of enzymes to break down most glycosidic bonds found in food sources. However, certain bonds, like the beta-1,4-glycosidic bond found in cellulose (a type of dietary fiber), cannot be broken down by the mammalian enzymes in the small intestine. Unlike the alpha-glycosidic bonds found in amylose and other digestible polysaccharides, beta bonds have a different spatial configuration that our enzymes cannot recognize and act upon. While some animals have symbiotic gut bacteria that produce cellulase to digest cellulose, human digestion lacks this capability. Therefore, these beta bonds pass through our system as indigestible fiber, supporting digestive health but not contributing direct nutritional value.