Core Concepts
In this article, you will be able to understand nucleic acids, their conformation and composition, their functions, and the different types. You will also know how this biomolecule metabolizes.
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Nucleic Acids
Nucleic acids are macromolecules consisting of nucleotide building blocks. Deoxyribonucleic acid and ribonucleic acid are the two types that occur naturally. All free-living organisms and some viruses have DNA, which serves as the ultimate blueprint for life. RNA is the genetic material of certain viruses, but it is also present in all living cells and plays a crucial part in several biological functions, including the synthesis of proteins. It is possible to degrade nucleic acids to produce sugars, phosphoric acid, and a variety of organic bases (purines and pyrimidines).
These molecules -nucleic acids- contain genetic material that is read by cells to create the RNA and proteins necessary for life.
Nucleotides
A nucleotide is the basic building molecule that forms DNA and RNA. A sugar molecule (deoxyribose in DNA and ribose in RNA), a phosphate group, and a base containing nitrogen make up this building molecule. The sugar and phosphate groups make up the DNA/RNA backbone. The bases used in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA uracil (U) changes places with thymine.
To fully understand these amazing building molecules go read our Nucleotides article!
Composition and Size – Nucleic Acids
In general, nucleic acids are fairly big molecules. Small interfering RNA, has 21 nucleotides, while a chromosome is a single molecule with 247 million base pairs. Researchers have thoroughly examined both of these molecules.
In nature, single-stranded RNA molecules and double-stranded DNA molecules exist most of the time. There are several exceptions, though. Some viruses have single-stranded DNA genomes, while others have double-stranded RNA genomes. In other cases, three- or four-stranded nucleic acid structures can also arise.
Nucleic Acid Types
Deoxyribonucleic Acid
DNA, or deoxyribonucleic acid, is the substance that houses hereditary information in humans and nearly all other animals. We can find DNA in the cell nucleus, for eukaryotes, and in the cytoplasm of prokaryotes. A minor quantity of DNA can also be found in the mitochondria. The four chemical bases that make up the informational code stored in DNA are adenine (A), guanine (G), cytosine (C), and thymine (C) (T). Nucleotides are ordered in two long strands to develop and sustain an organism, similar to how letters of the alphabet occur in a certain order to make words and phrases. Every person has more than 99 percent of the 3 billion bases that make up human DNA the same.
Adenine (A) and thymine (T) and cytosine (C) and guanine (G) are the bases that makeup DNA (G). A double helix is a spiral shape made up of two long strands of nucleotides. The sugar and phosphate molecules serve as the ladder’s handrails, while the base pair units serve as their rungs. The ability of DNA to replicate, or generate duplicates of itself, is a crucial characteristic. This is crucial because every new cell must include an identical replica of the DNA found in the old DNA when cells divide.
Ribonucleic Acid
Adenine (A), uracil (U), cytosine (C), and guanine (G) constitute the single strand of ribonucleic acid (RNA). The backbone of an RNA molecule consists of alternating phosphate groups and sugar ribose. Cells employ various types of RNA, such as messenger RNA, ribosomal RNA, and transfer RNA, in addition to rRNA. Certain viruses use RNA as their genetic material, and RNA also participates in gene expression regulation.
The development of several vaccines, medications, and even certain treatments, such as RNA interference, has made RNA quite well-liked in the scientific community today.
Artificial Nucleic Acids
Chemists have created and produced artificial nucleic acid analogs such as peptide nucleic acid, morpholino-locked nucleic acid, glycol nucleic acid, and threose nucleic acid. Each of them differs from naturally occurring DNA or RNA due to modifications to the molecules’ backbones.
To, know more about artificial nucleic acids and their applications we recommend this article.
Nucleic Acids and their Metabolism
DNA Metabolism
Accordingly, specialized cellular machinery carries out the three primary functions of DNA metabolism – replication, repair, and recombination. The integrity of the genetic code depends on correct DNA replication. Repairing errors that occur during replication or as a result of damage after replication is necessary. Recombination across genomes plays a crucial role in fostering variety within a species and aiding in DNA repair. Scientists have figured out the specifics of each procedure in prokaryotes, which have more streamlined, straightforward, and receptive machinery for study. Lastly, prokaryotes have been instrumental in understanding the details of these procedures, while eukaryotes appear to share many fundamental concepts.
RNA Metabolism
Comparatively to DNA, RNA establishes the connection between the genetic information contained in DNA and how cells function. Certain RNA molecules, such as the rRNAs and snRNAs, join together to form intricate ribonucleoprotein complexes that play specific roles in cells. While mRNAs control how proteins are made by the ribosome, other molecules, such as tRNAs, are important in protein synthesis. The metabolism of RNA happens in three separate stages. Firstly, it creates the precursor RNAs, a subset of the genome that is first replicated via transcription. Secondly, these precursors undergo processing to become usable, functionally mature RNAs.
When RNA molecules are in the form of mRNAs, they are used for translation. After usage, the bases regenerate while the RNAs are destroyed. The process of transcription replicates a particular DNA segment or gene to produce a specific RNA that encodes a single protein or serves a structural or catalytic function. During the process of translation, a ribosome decodes the information contained in mRNA molecules. Prokaryotic and eukaryotic species exhibit significant variations in transcription and translation.