Question

1. plants produce both starch and cellulose. why are we able to use starch as a food source and not cellulose? what beneficial digestive function does cellulose perform for our bodies?
2. monosaccharides are being joined using dehydration synthesis. if three water molecules are produced, what would the resulting molecule be?

a. monosaccharide
b. disaccharide
c. trisaccharide
d. polysaccharide

Explanation:

Step1: Enzymes for starch digestion

Humans have enzymes like amylase that can break - down starch into glucose for energy. We lack cellulase which is needed to break down cellulose.

Step2: Cellulose's digestive function

Cellulose is a type of dietary fiber. It adds bulk to the feces, promotes peristalsis (the muscular contractions of the digestive tract), and helps prevent constipation.

Step3: Dehydration synthesis of monosaccharides

In dehydration synthesis of monosaccharides, one water molecule is produced for each glycosidic bond formed. If 3 water molecules are produced, 4 monosaccharides are joined together, forming a tetrasaccharide (a type of polysaccharide). But among the given options, the closest related one is polysaccharide as it is a general term for polymers of monosaccharides.

Answer:

We can use starch as a food source because we have enzymes to break it down, and we lack enzymes for cellulose breakdown. Cellulose adds bulk to feces and aids in peristalsis. For question 6, d. Polysaccharide