Which statement best describes chemical digestion?

Which statement best describes chemical digestion?

• A. Absorption of nutrients.
• B. Breakup of food particles through digestive enzymes.
• C. Mechanical breakdown by chewing.
• D. Movement of chyme.

Answer: (B)

Chemical digestion is the breakdown of complex food substances into smaller, absorbable molecules through enzymatic and chemical reactions in the digestive system. Enzymes such as amylases, proteases, and lipases, often aided by stomach acid, cleave covalent bonds in carbohydrates, proteins, and fats. This enzymatic action converts nutrients into monosaccharides, amino acids, and fatty acids with monoglycerides, which can then be absorbed. That is why describing it as the breakup of food particles through digestive enzymes best captures what chemical digestion does. In contrast, mechanical digestion (like chewing) merely breaks food into smaller pieces without changing its chemical structure, and absorption or movement of chyme are separate processes. For example, starch is digested to simple sugars by amylases, proteins to amino acids by proteases, and fats to fatty acids and glycerol by lipases.

Chemical digestion is the breakdown of complex food substances into smaller, absorbable molecules through enzymatic and chemical reactions in the digestive system. Enzymes such as amylases, proteases, and lipases, often aided by stomach acid, cleave covalent bonds in carbohydrates, proteins, and fats. This enzymatic action converts nutrients into monosaccharides, amino acids, and fatty acids with monoglycerides, which can then be absorbed. That is why describing it as the breakup of food particles through digestive enzymes best captures what chemical digestion does. In contrast, mechanical digestion (like chewing) merely breaks food into smaller pieces without changing its chemical structure, and absorption or movement of chyme are separate processes. For example, starch is digested to simple sugars by amylases, proteins to amino acids by proteases, and fats to fatty acids and glycerol by lipases.