Which of the following occurs during digestion?

• A. Enzymatic breakdown of macromolecules into smaller subunits
• B. Synthesis of proteins from amino acids
• C. Conversion of glucose to glycogen
• D. Production of oxygen from carbon dioxide

Answer: (A)

Verified step by step guidance

1. Understand the process of digestion: Digestion is the biological process where food is broken down into smaller components that can be absorbed and utilized by the body.
2. Identify the key function of digestion: The primary goal is the enzymatic breakdown of macromolecules (such as carbohydrates, proteins, and lipids) into their smaller subunits (like monosaccharides, amino acids, and fatty acids).
3. Eliminate incorrect options: Synthesis of proteins from amino acids is a process of anabolism, not digestion. Conversion of glucose to glycogen occurs during glycogenesis, which is a storage process, not digestion. Production of oxygen from carbon dioxide is part of photosynthesis, which does not occur in human digestion.
4. Focus on enzymatic activity: During digestion, enzymes like amylase, protease, and lipase play a critical role in breaking down macromolecules into absorbable subunits. For example, amylase breaks down starch into glucose, protease breaks down proteins into amino acids, and lipase breaks down fats into glycerol and fatty acids.
5. Conclude that the correct answer is related to the enzymatic breakdown of macromolecules into smaller subunits, as this is the central function of digestion.