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The most significant molecules in cell biology are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), which are responsible for the storage and reading of genetic information that underpins all life. They are both linear polymers made up of sugars, phosphates, and bases, but there are some significant distinctions between them. These variances allow the two molecules to collaborate and perform their vital functions.
What are the different ways of representing DNA and RNA?
DNA
The hereditary substance in humans and almost all other animals is DNA. The DNA of nearly every cell in a person’s body is identical. The majority of DNA is contained in the cell nucleus (also known as nuclear DNA), although a tiny quantity is also present in the mitochondria (where it is called mitochondrial DNA or mtDNA). Mitochondria are cellular structures that convert food energy into a form that cells can use.
Adenine, guanine, cytosine, and thymine are the four chemical bases that make up DNA’s coding. Human DNA is made up of around 3 billion bases, with over 99 percent of those bases being identical in all humans.
Structure of DNA
The DNA molecules of a live organism contain the instructions it requires to grow, develop, and reproduce. Each cell has these instructions, which are passed down from parents to their children.
DNA is made up of nucleotides having nitrogenous groups, phosphate groups, and sugar groups. The order of the nitrogenous bases thymine, guanine, cytosine, and adenine determines the genetic code.
Genes are formed by the ordering of nitrogenous bases in DNA, which is required for protein creation. RNA is another nucleic acid that turns DNA genetic information into proteins.
The nucleotides are linked to form two long strands that spiral to form the double-helix structure, which resembles a ladder with the sugar and phosphate molecules serving as the sides and bases.
Types of DNA
DNA can be divided into three types:
A-DNA is a right-handed double helix that resembles B-DNA in appearance. When DNA becomes dehydrated, it converts to the A form, which protects it from extreme circumstances such as desiccation. In addition to removing the solvent from DNA, protein binding causes it to take on the shape of an A.
B-DNA, a right-handed helix, is the most prevalent DNA shape. The bulk of DNA has a B type form in normal physiological conditions.
Z-DNA is a left-handed DNA with a zig-zag double helix that coils to the left. It was found by Andres Wang and Alexander Rich. It is hypothesised to play a role in gene regulation since it is located before the start point of a gene.
RNA
RNA is a nucleic acid that has structural similarities to DNA and is found in all living organisms. RNA, unlike DNA, is almost always single-stranded. Instead of the deoxyribose found in DNA, an RNA molecule has a backbone consisting of alternating phosphate groups and the sugar ribose. Each sugar has one of four bases attached to it: adenine, uracil, cytosine, or guanine. In cells, there are three forms of RNA: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). Furthermore, some RNAs play a role in regulating gene expression. RNA serves as the genomic material for several viruses.
Structure of RNA
RNA is a single-stranded molecule composed of ribonucleotides linked together by phosphodiester bonds. A ribonucleotide in the RNA chain is made up of ribose (a pentose sugar), one of the four nitrogenous bases, and a phosphate group. The tiny structural difference between the sugars gives DNA more stability, which makes it better for storing genetic information, and RNA’s relative instability makes it better for short-term functions. RNA-specific pyrimidine uracil creates a complementary base pair with adenine instead of the DNA base thymine.
Despite the fact that RNA is single-stranded, most RNA molecules have significant intramolecular base pairing between complementary sequences inside the RNA strand, resulting in a predictable three-dimensional structure that is essential for their function.
Types of RNA
There are many different types of RNA, with the following being the most well-known and studied in the human body:
Transfer RNA (tRNA)
The tRNA assists the ribosomes in picking the correct protein or amino acids required by the organism. It is present at the ends of amino acids. This RNA connects the mRNA to the amino acid and is also known as soluble RNA.
Ribosomal RNA (rRNA)
rRNA, a component of ribosomes, is located in the cytoplasm of a cell where ribosomes are found. In all live cells, rRNA is required for the generation and translation of mRNA into proteins.
Messenger RNA (mRNA)
This type of RNA transmits instructions about the types of proteins required by body cells by transferring genetic material into ribosomes. Owing to their functions, certain types of RNA are known as mRNA. As a result, mRNA is crucial to the transcription and protein synthesis processes.
Conclusion
The nucleic acid known as DNA, short for deoxyribonucleic acid, is the unique transporter of genetic information in all organisms. DNA is made up of two molecular coils that are coiled around each other and chemically linked by bonds connecting adjacent nucleotides. The backbone of each long ladder-like DNA helix is made up of alternating sugars and phosphates. A “base” of the nitrogen-containing compounds, i.e., adenine, guanine, cytosine, or thymine, is attached to each sugar. A nucleotide is the name for each sugar-phosphate-base “rung.”
Nucleotides made up of a 5-carbon sugar ribose, a phosphate group, and a nitrogenous base make up RNA. Both these nucleic acids serve various functions and are an important component of the cells.
