Questions: What is the role of ribose and deoxyribose in the nucleic acids? They are the structural backbone. The act as the functional group for the nucleic acid. They act as enzymes in metabolic pathways. They provide energy for the nucleic acids.

The answer is the first one: They are the structural backbone.

Explanation for each option:

1. They are the structural backbone. - Correct. Ribose and deoxyribose are sugars that form the backbone of nucleic acids (RNA and DNA, respectively). They link with phosphate groups to create the sugar-phosphate backbone that supports the nucleotide bases.
2. They act as the functional group for the nucleic acid. - Incorrect. The functional groups in nucleic acids are primarily the nucleotide bases (adenine, thymine, cytosine, guanine, and uracil).
3. They act as enzymes in metabolic pathways. - Incorrect. Ribose and deoxyribose are not enzymes; they are sugars. Enzymes are typically proteins that catalyze biochemical reactions.
4. They provide energy for the nucleic acids. - Incorrect. While ribose is a component of ATP (adenosine triphosphate), which provides energy for cellular processes, in the context of nucleic acids, ribose and deoxyribose serve as structural components rather than direct energy sources.

Summary: Ribose and deoxyribose serve as the structural backbone of nucleic acids, forming the sugar-phosphate backbone that supports the nucleotide bases.