In order for genes to express themselves, an RNA molecule must be formed from a DNA molecule. This process is called transcription, and its key enzyme is RNA polymerase. The whole process takes place in the nucleus of the cell.
Initially, a DNA molecule opens at the point where the gene to be transcribed lies. This is due to the action of RNA polymerase, which promotes the opening and exposure of nucleotide sequences that will be transcribed. At this point, it is important to note that only one strand of DNA will be used for synthesis.
RNA polymerase will also guide ribonucleotide pairing, thus leading to stretching of the RNA strand. Nucleotides found in DNA differ from those found in RNA in that, in RNA, sugar is ribose (so called ribonucleotides) and the nitrogen base is uracil (U) instead of thymine (T). .
There are three types of RNA, messenger RNA, carrier RNA, and ribosomal RNA.
Gene is a sequence of distinct nucleotides that are part of a chromosome. Each gene encodes a particular sequence of a polypeptide chain (union of amino acids that make up the protein). The gene is formed by a sequence of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), the latter being responsible for cell protein synthesis.
