What are the differences between mechanical and chemical digestion?

Mechanical digestion involves physical breakdown of food, while chemical digestion involves enzymatic breakdown.

Mechanical digestion is the physical breakdown of food into smaller pieces, which increases the surface area available for chemical digestion. This process begins in the mouth with the teeth grinding and mashing food, and continues in the stomach where muscular contractions churn and mix the food with digestive juices. Mechanical digestion also occurs in the small intestine, where peristaltic contractions mix and move the food along the digestive tract.

Chemical digestion involves the enzymatic breakdown of food molecules into smaller, absorbable molecules. This process begins in the mouth with the enzyme amylase breaking down carbohydrates, and continues in the stomach where hydrochloric acid and enzymes break down proteins. The majority of chemical digestion occurs in the small intestine, where enzymes from the pancreas and intestinal lining break down carbohydrates, proteins, and fats.

Overall, mechanical and chemical digestion work together to break down food and prepare it for absorption into the bloodstream. Mechanical digestion physically breaks down food into smaller pieces, while chemical digestion uses enzymes to break down food molecules into absorbable nutrients.