1. DNA to mRNA (Transcription):
* DNA: The genetic code for a protein is stored in DNA within the nucleus of a cell.
* Transcription: The DNA sequence is copied into a messenger RNA (mRNA) molecule. This occurs within the nucleus, where the DNA unwinds and serves as a template for the mRNA synthesis.
2. mRNA to Protein (Translation):
* mRNA: The mRNA molecule travels from the nucleus to the cytoplasm, where it encounters ribosomes.
* Translation: The mRNA sequence is read by the ribosome, which uses the genetic code to assemble amino acids into a protein chain. Transfer RNA (tRNA) molecules bring the correct amino acids to the ribosome, guided by the mRNA sequence.
Overall Flow:
DNA → mRNA → Protein
Key Points:
* Central Dogma: This flow of genetic information from DNA to RNA to protein is known as the central dogma of molecular biology.
* Genetic Code: The mRNA sequence is read in codons (three-nucleotide units), each of which specifies a particular amino acid.
* Ribosomes: Ribosomes are the sites of protein synthesis.
* tRNA: tRNA molecules act as adapters, bringing the correct amino acids to the ribosome based on the mRNA code.
This process ensures that the genetic information encoded in DNA is accurately used to build proteins, which are essential for all cellular functions.
