Chapter 22, Problem 7SQ

Summary Introduction

Introduction: Both mechanical and chemical processesare involved in the digestion of food. Mechanical digestion involves the chewing and grinding of food. This breaks the food into smaller pieces that increase the surface area of food. The food particles then undergo chemical digestion, which cleaves the large molecules into smaller components.

Chemical digestion is important for the breaking down of the macromolecules such as proteins, carbohydrates, nucleic acids, fats, and phospholipids into simpler absorbable form. The macromolecules in its original form cannot pass through the cell membranes. Absorption takes place mainly in the small intestine.