Question

Animal gut does NOT possess the enzymes required for digesting

• A. glycogen
• B. starch
• C. cellulose
• D. proteins

Hint:

Remember that cellulose is not digestible by animals without microbial help due to the absence of the enzyme cellulase. Other polysaccharides like starch and glycogen are digestible.

Answer 1

The Correct Option is C

Step 1: Understand enzyme availability in the animal gut
The animal digestive system is well-equipped with enzymes such as:
Amylase for digesting starch,
Proteases for digesting proteins,
Glycosidase for breaking down glycogen.

Step 2: Analyze cellulose digestion
Cellulose is a polysaccharide made up of β-1,4-linked glucose units.
Animals lack the enzyme cellulase, which is required to hydrolyze these β-1,4 glycosidic bonds.

Step 3: Conclusion
Because animals (especially non-ruminants) do not produce cellulase, they cannot digest cellulose on their own.
In herbivores like cows or termites, microbial symbionts assist in cellulose digestion.