Mrs. Ruhala set up an experiment where she tested for the presence of monosaccharides in food. She took a cracker, and it tested negative for monosaccharides. Then she put the cracker in her mouth, chewed it for a few minutes, and then spit it out into a test tube. It now tested positive for monosaccharides. What happened? a An enzyme in her mouth broke down the polysaccharides in the cracker into monosaccharides. b Water in the saliva catalyzed the cracker proteins and broke them into monosaccharides. c The physical action of chewing broke down the lipids in the cracker and producing a positive reaction. d Mrs. Ruhala is a magical being and ewww.

Answer 1

The correct answer is a: An enzyme in her mouth broke down the polysaccharides in the cracker into monosaccharides.

Chewing the cracker mixes it with saliva, which contains the enzyme amylase. Amylase breaks down starch (a polysaccharide present in the cracker) into simpler sugars (monosaccharides), leading to a positive test for monosaccharides after the cracker was chewed and digested in the mouth.