Πώς Λειτουργούν το DNA και το RNA;

DNA is a complex molecule that forms the blueprint of life.Its structure is characterized by a distinctive double helix formation.Each strand of DNA is made up of nucleotides, which have three main components.A nucleotide consists of a deoxyribose sugar, a phosphate group, and a nitrogenous base.DNA bases pair in specific ways: Adenine pairs with Thymine using two hydrogen bonds.Guanine pairs with Cytosine using three hydrogen bonds, making their connection stronger.These specific base pairings are crucial for DNA replication and maintaining genetic information.Hydrogen bonds form between the bases through shared hydrogen atoms, holding the two DNA strands together.RNA is a single-stranded molecule that differs from DNA in several key ways.The main chemical differences are in the sugar component and one of the bases.There are three main types of RNA, each with a specific function in the cell.Messenger RNA, or mRNA, carries genetic information from DNA to the ribosomes.Transfer RNA, or tRNA, is responsible for transporting amino acids during protein synthesis.Ribosomal RNA, or rRNA, forms part of the ribosomes and helps in protein synthesis.These three types of RNA work together in protein synthesis, with each playing its crucial role.DNA replication begins when the double helix unwinds at specific points called replication origins.The enzyme helicase breaks the hydrogen bonds between base pairs, creating a replication fork.DNA synthesis occurs in both directions. The leading strand is synthesized continuously in the 5' to 3' direction.The lagging strand is synthesized in short segments called Okazaki fragments.During transcription, RNA polymerase binds to the DNA template strand.The DNA double helix temporarily unwinds, forming a transcription bubble.RNA nucleotides are added one by one, complementary to the DNA template strand.The RNA strand grows in the 5' to 3' direction as transcription proceeds.Once transcription is complete, the RNA strand is released and the DNA double helix reforms.