1. How does the food change in consistency and form?
The food we ingest undergoes digestion that involves both mechanical and chemical processes. This begins from the mouth where food is mechanically broken down into smaller pieces through chewing, and saliva, containing enzymes that aid in digesting starches, initiates a chemical process to prepare the food for digestion. As it moves to the stomach, more breakdown happens with gastric juices turning proteins into a watery mixture called chyme. In the small intestine, bile and pancreatic enzymes act on fats, carbohydrates, and proteins, turning them into absorbable molecules for the small intestine. Nutrients are absorbed through the walls of the small intestine while water and electrolytes get taken in the large intestine, and the remaining chyme becomes more solid before turning into feces. Throughout this process, the consistency and form of the food change from a solid, complex structure to a liquid (chyme) and, eventually, a semi-solid (feces) form.
2. How could the body absorb the nutrients from the foods we eat?
The process of nutrient absorption is mostly done in the small intestine, where enzymes break down complex molecules into simpler forms. Nutrients such as carbohydrates, proteins, and fats are then absorbed through the intestinal walls into the bloodstream. Once absorbed, these nutrients are transported via the circulatory system to various cells and tissues in the body, where they are utilized for energy, growth, and maintenance of essential physiological functions.