Question 2

A carbohydrate

A molecule consisting of a chain of glucose monomers linked together is classified as a carbohydrate. This is because carbohydrates are polymers made up of sugar units, specifically monosaccharides like glucose.

A) A protein

A protein is a polymer made up of amino acids, not glucose. While proteins are essential biomolecules, they do not consist of glucose units and therefore cannot be the correct answer in this context.

B) A nucleic acid

Nucleic acids, such as DNA and RNA, are polymers made from nucleotide monomers. They are fundamentally different from carbohydrates, which are made from sugar monomers like glucose, making this option incorrect.

C) A lipid

Lipids are a diverse group of hydrophobic molecules that include fats and oils, but they do not consist of glucose monomers. Therefore, this option does not fit the description of a molecule made from glucose.

D) A carbohydrate

Carbohydrates are organic compounds characterized by the presence of carbon, hydrogen, and oxygen, typically in a ratio of 1:2:1. A polymer of glucose, such as starch or glycogen, falls squarely under this category, confirming that this is the correct answer.

Conclusion

The identification of the molecule as a carbohydrate is definitive, as it is specifically composed of glucose monomers, which are the building blocks of carbohydrates. The other options fail to align with the structural characteristics and composition of the molecule in question. Thus, D is the only accurate classification.