Nucleic Acids

Know about nucleic acid, nucleic acid research, their occurrence, nomenclature and types in detail. You will also learn about the functions of DNA and RNA in cells.

Introduction

Nucleic acids are naturally occurring chemical substances that make up the genetic material and act as the major information-carrying molecules in cells. Nucleic acids are abundant in all living beings, where they produce, encode and store information for every living cell in every life form on the planet. They then transfer and express the information both inside and outside the cell nucleus to the cell’s internal functions and eventually to the next cell.

Occurrence and Nomenclature

DNA and RNA are members of a family of biopolymers known as nucleic acids, and the term nucleic acid is synonymous with the term polynucleotide. The presence of phosphate groups in nucleic acids led to their original discovery within the nucleus (related to phosphoric acid). Although nucleic acids were first discovered in the nuclei of eukaryotic cells, they are now recognised to exist in all living things, including bacteria, archaea, mitochondria, chloroplasts, and viruses (There is debate as to whether viruses are living or nonliving). All live cells (excluding mature red blood cells) have both DNA and RNA, whereas viruses contain either DNA or RNA but seldom both. The nucleotide is the most basic component of biological nucleic acids, consisting of a pentose sugar (ribose or deoxyribose), a phosphate group, and a nucleobase. Nucleic acids are also produced in the laboratory by the use of enzymes.

Molecular Composition and Size

Nucleic acids are big molecules in general. DNA molecules are the largest single molecules yet discovered. From 21 nucleotides (small interfering RNA) to huge chromosomes, biological nucleic acid molecules have been investigated extensively (human chromosome 1 is a single molecule that contains 247 million base pairs.

Natural DNA molecules are double-stranded in most circumstances, while RNA molecules are single-stranded.

There are a few exceptions: some viruses have double-stranded RNA genomes. In contrast, others have single-stranded DNA genomes, and nucleic acid structures with three or four strands can arise in specific circumstances.

Nucleic acids are nucleotide-based linear polymers (chains). Each nucleotide is made up of three parts: a purine or pyrimidine nucleobase (also known as nitrogenous base or simply base), a pentose sugar, and an acidic phosphate group. A nucleoside is a substructure that consists of a nucleobase and sugar. The types of nucleic acids vary.

Types

Deoxyribonucleic acid

Deoxyribonucleic acid or DNA is a nucleic acid that contains genetic instructions that all living organisms use to develop and function. Genes are DNA segments that carry this particular genetic information. Other DNA sequences, meanwhile, have structural purposes or play a role in regulating how this genetic information is used. DNA is one of the three primary macromolecules required for all known forms of life, along with RNA and proteins. DNA is made up of 2 long polymers of simple units known as nucleotides, which have sugar and phosphate groups as backbones and are connected by ester bonds. These two strands are antiparallel because they go in completely opposite directions. Nucleobases are one of four types of molecules that are attached to each sugar (informally, bases). The information is encoded by the sequence of the four nucleobases along the backbone.

Ribonucleic acid

Ribonucleic acid (RNA) is responsible for translating genetic information from genes into protein amino acid sequences. Transfer RNA (tRNA), messenger RNA (mRNA), and ribosomal RNA are the three universal forms of RNA (rRNA). Messenger RNA directs protein synthesis by carrying genetic sequence information between DNA and ribosomes. It also transmits instructions from the nucleus to the ribosome. Ribosomal RNA reads DNA sequences and catalyses the creation of peptide bonds. Transfer RNA is responsible for decoding mRNA and serving as a carrier molecule for amino acids required in protein production. Many other types of RNA have also been discovered.

The Functions of DNA and RNA in Cells

Nucleic acids, which are macromolecules made up of nucleotide units, come in two types: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) (RNA). DNA is the genetic material that can be found in all living things, from single-celled bacteria to multicellular animals like you and me. Although some viruses employ RNA rather than DNA as their genetic material, they are not really alive (since they cannot reproduce without help from a host).

From DNA to RNA to proteins, everything is interconnected.

Many genes code for protein products, which means they specify the amino acid sequence utilised to make a certain protein. However, before this information can be used to make proteins, an RNA copy (transcript) of the gene must be created. Messenger RNA (mRNA) is a form of RNA that acts as a link between DNA and ribosomes, which are molecular engines that read mRNA sequences and use them to make proteins. The “core dogma” of molecular biology is the pathway from DNA to RNA to protein.