What process involves the chemical breakdown of food into tiny particles?

The process that involves the chemical breakdown of food into tiny particles is digestion. Digestion is a complex process that starts in the mouth and continues in the stomach and intestines, where various enzymes and acids break down food into smaller, absorbable components. This transformation is essential for the body to access nutrients, as it allows carbohydrates, proteins, and fats to be broken down into molecules that can be absorbed into the bloodstream and utilized by the body's cells for energy, growth, and repair.

Secretion refers to the process by which substances such as enzymes, hormones, and digestive juices are released, which supports digestion but is not the breakdown itself. Absorption is the stage following digestion, where the broken-down nutrients are taken up into the bloodstream and distributed throughout the body. Excretion is the elimination of waste products from the body, which occurs after nutrients have been absorbed and utilized, thus unrelated to the breakdown of food.