Question

which of the following is an example of chemical digestion? choose one option a a whole grape enters your mouth and your teeth break it up into smaller pieces that are easier to swallow. b the bagel you ate this morning eventually leaves your body as a waste material called feces. c your body uses the eggs you had for breakfast for energy, growth and healing. d little pieces of chewed up hamburger are broken down into smaller molecules by enzymes.

Explanation:

To determine the example of chemical digestion, we analyze each option:

• Option A: Teeth breaking food into smaller pieces is mechanical digestion (physical breakdown), not chemical.
• Option B: Feces elimination is egestion, not digestion (digestion involves breaking down food for absorption).
• Option C: Using nutrients for energy/growth is assimilation (after digestion and absorption), not digestion itself.
• Option D: Enzymes breaking food into smaller molecules (like proteins to amino acids) is chemical digestion, as it involves chemical reactions (enzyme - catalyzed) to change the chemical structure of food.

Answer:

D. Little pieces of chewed up hamburger are broken down into smaller molecules by enzymes.