1. How does the food change in consistency and form?
- Chemical digestion, in which enzymes and acids break down complex molecules into simpler ones, and mechanical digestion, such as chewing and churning in the stomach which physically breaks food into smaller pieces, both alter the consistency and form of food. For example, saliva starts breaking down carbohydrates, while stomach acids dissolve proteins.
2. How could the body absorb the nutrients from the foods we eat?
- The small intestine is where the body absorbs nutrients, and the surface area for absorption is increased by microscopic structures called villi (tiny finger-like structures). Fatty acids, amino acids, and glucose enter the bloodstream or lymphatic system through the intestinal walls. These nutrients are then delivered to cells for growth, repair, and energy.