Which process involves the breakdown of food into smaller molecules?

Digestion is the process that involves breaking down food into smaller molecules, which is crucial for the body to use the nutrients contained in the food. This process can be divided into mechanical digestion, where physical breakdown occurs (such as chewing), and chemical digestion, where enzymatic reactions transform complex molecules into simpler forms that can be absorbed by the body.

During digestion, macromolecules like carbohydrates, proteins, and fats are broken down into their respective monomers: sugars, amino acids, and fatty acids. This breakdown occurs in different parts of the digestive system, such as the mouth, stomach, and small intestine, facilitating the subsequent absorption of these nutrients into the bloodstream for use by the body’s cells.

The other processes mentioned serve different functions; absorption pertains to the uptake of these smaller molecules into the cells of the intestinal lining, ingestion refers to the act of taking food into the digestive system, and elimination involves the expulsion of undigested food and waste products from the body. Understanding these distinct processes is key to comprehending how the digestive system functions as a whole.