What is the difference between digestion and absorption?

Digestion and absorption are two essential stages of the digestive process, differing in function, mechanism, and location.

Digestion is the process of breaking down complex food substances into simpler, soluble molecules using mechanical and chemical methods.

Absorption is the process by which these digested nutrients pass through the intestinal walls into the bloodstream or lymph for distribution throughout the body.

Key differences:

• Definition:
  Digestion breaks down food; absorption takes nutrients into the body.

• Process type:
  Digestion involves mechanical (chewing, churning) and chemical (enzymatic) processes; absorption is mainly a physical and physiological process involving transport across membranes.

• Location:
  Digestion occurs in the mouth, stomach, and small intestine; absorption mainly occurs in the small intestine (especially in villi).

• End result:
  Digestion produces simple molecules (glucose, amino acids, fatty acids); absorption transfers these nutrients into blood or lymph.

• Function:
  Digestion prepares nutrients; absorption delivers them to cells.

In simple terms: Digestion breaks food into simple nutrients, while absorption moves those nutrients into the bloodstream for use by the body.