Question

The pentose deoxyribose is found in DNA, whereas ___________ is found in RNA.

Short answer

The pentose deoxyribose is found in DNA, whereas ribose is found in RNA.

Step-by-step solution

Understand the structure of nucleic acids

Nucleic acids (DNA and RNA) are made up of three main components: a phosphate group, a pentose sugar, and a nitrogenous base. The difference between DNA and RNA lies in their sugar component. The pentose sugar in DNA is deoxyribose, while RNA has a different pentose sugar.

Identify the pentose sugar in RNA

The pentose sugar found in RNA is ribose. Ribose differs from deoxyribose by having an extra hydroxyl group (-OH) on the 2' carbon atom of the sugar ring. Therefore, the pentose deoxyribose is found in DNA, whereas ribose is found in RNA.

Key concepts

DNA

DNA stands for Deoxyribonucleic Acid and is the hereditary material found in humans and almost all other organisms. Most DNA is located in the cell nucleus and a small amount is found in mitochondria. DNA carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses.
DNA structure is often likened to a twisted ladder, the iconic double helix. The rungs of this ladder are made up of base pairs held together by hydrogen bonds, while the sides of the ladder consist of alternating sugar and phosphate groups.

• DNA contains the pentose sugar called deoxyribose, which is part of its backbone.
• The unique sequence of bases in DNA determines the unique genetic instructions.
• DNA is responsible for storing and transferring genetic information in living organisms.

RNA

RNA, or Ribonucleic Acid, plays crucial roles in coding, decoding, regulation, and expression of genes. Unlike DNA, RNA is typically single-stranded and is involved in protein synthesis and other vital cellular processes.
There are several types of RNA, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), each serving different functions in the cell.

• RNA contains the pentose sugar ribose, which distinguishes it from DNA.
• RNA is usually found both in the nucleus and the cytoplasm of a cell.
• Unlike DNA, RNA can catalyze biological reactions, much like enzymes.

pentose sugar

Pentose sugars are five-carbon sugars that are essential components of nucleic acids. They form part of the backbone structure of nucleic acids by connecting with phosphate groups.
These sugars play a critical role in the structural stability and function of nucleic acids by holding together the chain of nucleotides.

• Pentose sugars can either be in the form of ribose or deoxyribose depending on whether they are part of RNA or DNA respectively.
• The difference in structure between ribose and deoxyribose is minimal yet fundamental to their specific functions.

deoxyribose

Deoxyribose is a type of pentose sugar that is a crucial component in the structure of DNA. It is a modified sugar, lacking one oxygen atom ( Oxygen missing in deoxyribose is on the 2' carbon as opposed to ribose, which has one hydrogen and one hydroxyl group attached there. )
This modification makes DNA more stable compared to RNA, which is why DNA serves as the primary storage of genetic information.

• Having fewer oxygen atoms makes DNA less reactive and more suited to long-term storage of genetic data.
• Deoxyribose in DNA carries the genetic blueprint necessary for cellular function and organismal development.

ribose

Ribose is another type of pentose sugar that is an integral part of RNA's structure. Unlike deoxyribose, ribose contains a hydroxyl group (OH) attached to its 2' carbon atom.
This small difference makes RNA more flexible and reactive compared to DNA, contributing to its role in various cellular processes, including acting as a messenger between DNA and protein assembly machinery.

• Ribose helps RNA to fold into diverse three-dimensional structures necessary for its functions.
• The presence of the hydroxyl group makes RNA less stable than DNA, but perfect for its dynamic roles.