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.

Question

What happened?

a
Mrs. Ruhala is a magical being and ewww.
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
An enzyme in her mouth broke down the polysaccharides in the cracker into monosaccharides.

Answer 1

The correct answer is:

d An enzyme in her mouth broke down the polysaccharides in the cracker into monosaccharides.

When Mrs. Ruhala chewed the cracker, the salivary enzyme amylase began the process of breaking down starches (which are polysaccharides) into simpler sugars, including monosaccharides. This is why the tested sample from the chewed cracker turned positive for monosaccharides after the chewing process.