Describe how genetic information is expressed as proteins. In you answer, describe DNA replication, transcription and translation.

The expression of genetic information as protein is a complex process consisting of several steps. Genetic information is encoded in DNA that represents a linear sequence of nucleotides. The first step of the realization of genetic information is its storage and amplification that is controlled by replication. Replication is the process of the formation of two daughter DNA molecules based on the parent DNA molecule. Using special enzymes, the double helix of maternal DNA is decomposed into two strands, a second strand is built on each strand formed, producing two identical daughter DNA molecules, which are then twisted into separate spirals. During the subsequent division of the maternal cell, each daughter cell receives one copy of the DNA molecule, which is identical to the DNA of the original maternal cell. This process ensures the accurate transfer of genetic information between generations. DNA consists of codons (three nucleotides) that encode amino acid sequences of proteins. As a result, nucleotide sequences in the DNA molecule correspond to amino acid sequences in protein. As a result, information encoded in DNA determines the structure and functions of proteins that control most of the processes that occur in living organisms. DNA is a large and stable molecule that cannot be directly used as a template for protein synthesis. The process requires a mediator - mRNA. This RNA is consists of nucleotides that correspond to the sequence of nucleotides in DNA. mRNA is relatively small, compact and can be further used as a template for the synthesis of protein. The process of mRNA synthesis on DNA is called transcription. As a result, transcription is the process of copying genetic information from DNA to RNA, in particular to mRNA. Transcription is carried out by the RNA polymerase, that synthesizes RNA according to the principle of complementarity. Genetic information transcribed in mRNA is further translated into a protein sequence consisting of amino acids that correspond to the nucleotide sequence of mRNA. The process is catalyzed by ribosomes that are nonmembranous RNA-protein complexes. They use mRNA and amino acids attached to specific tRNA to decode the genetic information. mRNA contains codons that correspond to a certain amino acid. Specific tRNA contains anticodons that can recognize the codon. If the correct codon-anticodon pair is present, amino acids are attached resulting in the formation of the peptide bond. This continuous process leads to the formation of a protein that gains its structure. All these processes are required to express genetic information as proteins.