A pentose sugar is a part of the monomer used to build which type of macromolecule? a. polysaccharides b. nucleic acids c. phosphorylated glucose d. glycogen
The Correct Answer and Explanation is:
The correct answer is b. nucleic acids.
A pentose sugar is a type of monosaccharide (simple sugar) that contains five carbon atoms. Pentose sugars are important components of nucleic acids like DNA and RNA. In the context of nucleic acids, the pentose sugar is specifically referred to as deoxyribose in DNA and ribose in RNA.
In DNA (deoxyribonucleic acid), the sugar component is deoxyribose, which has five carbon atoms and a hydroxyl group (–OH) attached to the 3′ carbon and a hydrogen atom (–H) attached to the 2′ carbon. The lack of an oxygen atom on the 2′ carbon is why it is called “deoxy.”
In RNA (ribonucleic acid), the sugar component is ribose, which is structurally similar to deoxyribose, except that ribose has a hydroxyl group (–OH) attached to both the 2′ and 3′ carbons. This slight structural difference gives RNA some unique chemical properties that influence its role in protein synthesis and other cellular processes.
The pentose sugars in these nucleic acids are linked to phosphate groups and nitrogenous bases (adenine, guanine, cytosine, thymine, and uracil) to form the nucleotide units that make up the polymer chains of DNA and RNA. These nucleotides are joined together by phosphodiester bonds to form the long strands of the nucleic acid.
In contrast, polysaccharides (like starch or cellulose) are made from monosaccharides, but they typically contain hexose sugars (six-carbon sugars), such as glucose, rather than pentose sugars. Therefore, pentose sugars are specifically associated with the structure of nucleic acids, not polysaccharides or other options.
