HUMAN NUTRITION

Detailed explanation-1: -Mechanical digestion involves physically breaking down food substances into smaller particles to more efficiently undergo chemical digestion. The role of chemical digestion is to further degrade the molecular structure of the ingested compounds by digestive enzymes into a form that is absorbable into the bloodstream.

Detailed explanation-2: -Saliva contains the salivary amylase enzyme, which digests carbohydrates (starches), and mucus (a thick liquid), which softens food into a bolus. Ingestion starts both chemical and mechanical digestion.

Detailed explanation-3: -Chemical digestion breaks large food molecules down into their chemical building blocks, which can then be absorbed through the intestinal wall and into the general circulation. Intestinal brush border enzymes and pancreatic enzymes are responsible for the majority of chemical digestion.

Detailed explanation-4: -Chemical digestion, through a process called hydrolysis, uses water and digestive enzymes to break down the complex molecules.

Detailed explanation-5: -Mechanical digestion is physical digestion done by teeth. Churning of food into smaller substances is an example of mechanical digestion. Breaking down food into a smaller substance is a helpful process so that food can easily undergo chemical digestion.