DNA (Deoxyribonucleic Acid)

DNA (Deoxyribonucleic Acid) Introduction: DNA, also known as deoxyribonucleic acid, is the fundamental substance in nearly all living things that passes on traits from one generation to another. It holds the genetic guidelines for growth, development, operation and reproduction of an organism. The structure of DNA can be described as a pair of long polymers made up nucleotide units that form into double helix shape. Structure of DNA: Double Helix: DNA's structure is a double helix, resembling a twisted ladder. Nucleotides: The building blocks of DNA, each consisting of: A phosphate group. A five-carbon sugar called deoxyribose. A nitrogenous base (Adenine (A), Thymine (T), Cytosine (C), or Guanine (G)). Base Pairing: Adenine pairs with Thymine (A-T) via two hydrogen bonds. Cytosine pairs with Guanine (C-G) via three hydrogen bonds. This complementary base pairing is crucial for the replication and function of DNA. Functions of DNA: Genetic Information Storage: DNA stores genetic information used for the development and functioning of organisms. DNA, which is made up of genes or specific sequences, possesses the instructions for building proteins. These protein units have multiple roles within the body. Replication: Before a cell separates, there is doubling of the DNA so that every fresh cell will possess an exact replica of the DNA. This involves the separation of two strands in a double helix, and each one being used as a guide for creating another strand. Transcription and Translation: Transcription is the process of copying a segment of DNA into mRNA (messenger RNA). Occurs in the nucleus. RNA polymerase enzyme synthesizes mRNA based on the DNA template. Translation: The process by which mRNA is decoded to synthesize proteins. Occurs in the cytoplasm at the ribosome. The job of the tRNA (transfer RNA) is to carry amino acids and pair them with matching codons on the mRNA, so that a protein can be constructed. Genetic Code: The genetic code, which we can also call the protein synthesis code, is basically a group of rules that describes how information carried by mRNA gets converted into proteins. It is universal among almost all organisms. Codons are found in messenger RNA (mRNA). They comprise three nucleotides each and match up with particular amino acids or halt indicators when making proteins. DNA Replication: Semi-Conservative Process: Every fresh DNA molecule is formed by one old (parental) strand and another recently created strand. Key Enzymes Involved: Helicase: Unwinds the DNA double helix. DNA Polymerase: Synthesizes the new DNA strand by adding nucleotides to the existing chain. Ligase: It shuts the spaces between fresh-made DNA pieces (Okazaki fragments) of the lagging strand. Mutations: Alterations in the DNA sequence that can cause differences in protein form and role. Errors in DNA copying, contact with mutagens like chemicals or radiation, and also viruses can cause a mutation. A few mutations are not harmful, but many can cause diseases or help in the development of an individual. DNA Technology: Recombinant DNA Technology: Involves combining DNA from different organisms to create new genetic combinations. Used in genetic engineering, gene therapy, and the production of insulin and other medications. Polymerase Chain Reaction (PCR): A method used to increase the amount of small DNA sections for different uses, such as in forensic science, medical diagnosis and study purposes. DNA Sequencing: sequence of nucleotides in a DNA molecule. Determining the exact Used in genomics, evolutionary biology, and personalized medicine. Conclusion: DNA, the basic substance of life, contains code for constructing and preserving living things. Knowing about its composition, job, and the activities related to copying or expressing it are crucial in areas such as genetics, biotechnology, medicine etcetera. DNA techniques keep pushing forward science and medical fields by giving fresh chances for healing illnesses and comprehending life down at molecule stage.