Which of the following is NOT considered a biological macromolecule?

• A. Lipid
• B. Glucose
• C. Nucleic acid
• D. Protein

Answer: (B)

Verified step by step guidance

1. Understand the definition of a biological macromolecule: Biological macromolecules are large, complex molecules that are essential for life. They include carbohydrates, lipids, proteins, and nucleic acids, which are typically polymers made up of smaller subunits (monomers).
2. Analyze each option: Lipids, nucleic acids, and proteins are all considered biological macromolecules because they are large molecules with specific biological functions. Lipids, for example, are involved in energy storage and membrane structure; nucleic acids store genetic information; and proteins perform a wide range of functions, including enzymatic and structural roles.
3. Consider the structure of glucose: Glucose is a monosaccharide, which is a simple sugar and a building block of carbohydrates. While it is biologically important, it is not a macromolecule because it is a small molecule and not a polymer.
4. Compare glucose to the other options: Unlike lipids, nucleic acids, and proteins, glucose does not meet the criteria of being a macromolecule. It is a monomer that can combine with others to form larger carbohydrate polymers, such as starch or glycogen.
5. Conclude that glucose is the correct answer: Based on the analysis, glucose is NOT considered a biological macromolecule, while lipids, nucleic acids, and proteins are.