Which three elements are found in all biological macromolecules?

• A. Nitrogen, phosphorus, and sulfur
• B. Iron, magnesium, and chlorine
• C. Calcium, potassium, and sodium
• D. Carbon, hydrogen, and oxygen

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the term 'biological macromolecules.' These are large molecules essential for life, including carbohydrates, lipids, proteins, and nucleic acids.
2. Step 2: Recognize that all biological macromolecules share a common backbone structure made of carbon atoms. Carbon is versatile and forms the basis of organic chemistry.
3. Step 3: Note that hydrogen is a key element in biological macromolecules, as it is involved in forming bonds with carbon and other elements, contributing to the structure and function of these molecules.
4. Step 4: Identify oxygen as another essential element. Oxygen is involved in functional groups like hydroxyl (-OH) and carbonyl (C=O), which are critical for the properties and reactivity of macromolecules.
5. Step 5: Conclude that carbon, hydrogen, and oxygen are the three elements found in all biological macromolecules, as they form the fundamental framework of these molecules.