Which sugar portions provide carbon skeletons for nucleic acids?

Prepare for the Foundations of Biology Exam 1. Dive into key biological concepts with multiple choice questions, hints, and explanations. Ace the exam with our efficient study methods!

Multiple Choice

Which sugar portions provide carbon skeletons for nucleic acids?

The sugars that provide the backbone of nucleic acids are five-carbon sugars: ribose in RNA and deoxyribose in DNA. Each nucleotide contains one of these pentoses, a phosphate, and a nitrogenous base. The sugar forms the carbon framework that the phosphate groups link to, creating the sugar–phosphate backbone of the strand, with the base attached to the 1' carbon. The difference between ribose and deoxyribose is at the 2' position: ribose has a hydroxyl group there, while deoxyribose has only a hydrogen, which makes DNA more chemically stable and RNA more reactive. The other sugars listed—glucose, fructose, and galactose—are six-carbon sugars used primarily for energy metabolism, not for constructing the nucleic acid backbone.

The sugars that provide the backbone of nucleic acids are five-carbon sugars: ribose in RNA and deoxyribose in DNA. Each nucleotide contains one of these pentoses, a phosphate, and a nitrogenous base. The sugar forms the carbon framework that the phosphate groups link to, creating the sugar–phosphate backbone of the strand, with the base attached to the 1' carbon. The difference between ribose and deoxyribose is at the 2' position: ribose has a hydroxyl group there, while deoxyribose has only a hydrogen, which makes DNA more chemically stable and RNA more reactive. The other sugars listed—glucose, fructose, and galactose—are six-carbon sugars used primarily for energy metabolism, not for constructing the nucleic acid backbone.

More practice questions