Question

The basic linkage in DNA or RNA between the sugar molecule and phosphoric acid is a phosphate linkage.

Short answer

The phosphate linkage, also known as a phosphodiester bond, is a crucial connection between sugar molecules and phosphoric acid in both DNA and RNA. This linkage forms the sugar-phosphate backbone of nucleic acids by binding to the 5' carbon atom of one sugar molecule and the 3' carbon atom of another sugar molecule through ester bonds. The phosphate linkage ensures the stability and linear structure of DNA and RNA molecules, enabling them to carry genetic information.

Step-by-step solution

Introduction to DNA and RNA

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are nucleic acids that play crucial roles in storing and translating genetic information. Both DNA and RNA are composed of three primary components: a sugar molecule, a phosphate group, and a nitrogenous base.

Understanding the Sugar Molecule

In DNA, the sugar molecule is called deoxyribose, whereas, in RNA, it is called ribose. The difference between these two sugars lies in the presence of a hydroxyl group (-OH) at the 2' carbon atom in ribose, which is replaced by a hydrogen atom in deoxyribose.

Phosphate Group

Phosphate groups, which consist of one phosphorus atom and four oxygen atoms (PO4), are crucial in forming the backbone of nucleic acids. They create a connection between sugar molecules in DNA and RNA by attaching to the 5' carbon atom of one sugar molecule and the 3' carbon atom of another.

Nitrogenous Bases

Nitrogenous bases are heterocyclic compounds containing nitrogen atoms, and they are attached to the 1' carbon atom of the sugar molecule. There are five main nitrogenous bases: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U). In DNA, A pairs with T and G pairs with C; in RNA, A pairs with U and G pairs with C.

Phosphate Linkage in DNA and RNA

The phosphate linkage, also known as a phosphodiester bond, connects the sugar molecule and phosphoric acid in DNA and RNA. These linkages create the sugar-phosphate backbone of the nucleic acids. The phosphate group binds to the 5' carbon atom of one sugar molecule and the 3' carbon atom of another sugar molecule through ester bonds, forming a strong and stable connection between nucleotide units in the DNA or RNA strand. Thus, the phosphate linkage ensures the stability and linear structure of the DNA and RNA molecules, enabling them to carry genetic information.

Key concepts

DNA and RNA structure

DNA and RNA are vital molecules in living organisms, responsible for storing and transmitting genetic information. Their structure consists of three main parts: a sugar molecule, a phosphate group, and a nitrogenous base. These form the backbone of the DNA and RNA strands. The key difference between DNA and RNA lies in their sugar components. DNA, or deoxyribonucleic acid, contains deoxyribose, whereas RNA, or ribonucleic acid, contains ribose.

This difference in sugars affects their structure and function. DNA is generally double-stranded and stable, suitable for long-term genetic storage. RNA is usually single-stranded, more versatile, and plays a vital role in protein synthesis and gene expression.

Phosphodiester bond

Phosphodiester bonds are crucial in forming the backbone of DNA and RNA. They are the bonds that connect the sugar molecule to the phosphate group along the nucleic acid strands. This connection occurs between the 5' carbon of one sugar and the 3' carbon of another sugar, creating a continuous chain.

These bonds are strong and help maintain the integrity and stability of the DNA and RNA molecules. The phosphodiester linkage plays a critical role in the formation of a highly stable sugar-phosphate backbone, capable of withstanding many cellular processes that DNA and RNA undergo.

Sugar-phosphate backbone

The sugar-phosphate backbone of nucleic acids serves as the primary structural framework of DNA and RNA. Formed by alternating sugar and phosphate groups, it provides support and stability to the molecule.

The backbone not only preserves the linear structure of the nucleic acid but also ensures that the nitrogenous bases are oriented correctly for base pairing. In DNA, the sugar molecule is deoxyribose, and in RNA, it is ribose. Each sugar in the backbone is connected to a phosphate group by phosphodiester bonds, creating a robust and resistant structure.

Nucleotide units

Nucleotide units are the building blocks of DNA and RNA. Each nucleotide consists of three components: a nitrogenous base, a sugar molecule, and a phosphate group. These nucleotides link together to form long strands of nucleic acids.

There are five main nitrogenous bases that make up nucleotides: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U). In DNA, A pairs with T, and G pairs with C; in RNA, A pairs with U, and G pairs with C. These base pairs are essential for transferring genetic information.

Genetic information storage

The structure of DNA and RNA allows them to effectively store and transmit genetic information. This is primarily due to the sequence of nitrogenous bases along the nucleic acid strands, which represents the genetic code.

DNA acts as the long-term storage of genetic instructions, forming a stable double-helix structure, while RNA is typically involved in gene expression and the synthesis of proteins. The stability and fidelity of this genetic information depend heavily on the phosphodiester bond and sugar-phosphate backbone, which maintain the integrity of the sequence.