Which of the following lists ranks these molecules in the correct order by size from smallest to largest?

• A. Water, sucrose, glucose, protein
• B. Protein, water, glucose, sucrose
• C. Water, protein, sucrose, glucose
• D. Glucose, water, sucrose, protein
• E. Water, glucose, sucrose, protein

Answer: (E)

Verified step by step guidance

1. Understand the molecular structure and size of each molecule: Water (H₂O) is a small molecule with a simple structure. Glucose (C₆H₁₂O₆) is a monosaccharide, a simple sugar with a larger structure than water. Sucrose (C₁₂H₂₂O₁₁) is a disaccharide, composed of two monosaccharides, making it larger than glucose. Proteins are large, complex molecules made up of amino acids, significantly larger than the other molecules listed.
2. Compare the molecular weights: Water has a molecular weight of approximately 18 g/mol. Glucose has a molecular weight of about 180 g/mol. Sucrose has a molecular weight of approximately 342 g/mol. Proteins vary greatly in size, but even small proteins have molecular weights in the thousands of g/mol.
3. Rank the molecules by size based on their molecular weights and structures: Start with the smallest, which is water, followed by glucose, then sucrose, and finally protein as the largest.
4. Review the options provided in the problem: Compare the order you determined with the options given. The correct order should match one of the options.
5. Identify the correct answer: The correct order by size from smallest to largest is Water, glucose, sucrose, protein, which matches the given correct answer.