What is digestion?

• A. Breakdown of food into smaller forms that can be absorbed and used
• B. Absorption of nutrients into the bloodstream
• C. Chemical reactions that produce energy
• D. Elimination of waste

Answer: (A)

Digestion is the breakdown of food into smaller forms that can be absorbed and used by the body. It involves mechanical actions like chewing and stomach churning, plus chemical actions with enzymes and acids that split carbohydrates, proteins, and fats into simpler units. By turning food into these smaller, soluble pieces, digestion prepares nutrients for absorption in the small intestine, where they pass into the bloodstream or lymph. Remember, absorption is about uptake of nutrients, while digestion is about breaking them down; energy production refers to cellular respiration, and elimination of waste is excretion.