geenitoiminnasta

Geenitoiminta refers to the process by which genetic information from a gene is used to synthesize a functional gene product, most commonly a protein. This process is fundamental to all known life and involves two main stages: transcription and translation.

Transcription is the synthesis of an RNA molecule from a DNA template. This occurs in the nucleus of eukaryotic cells. The DNA sequence of a gene is copied into a complementary messenger RNA (mRNA) molecule. This mRNA then carries the genetic code out of the nucleus to the ribosomes.

Translation is the synthesis of a protein from the mRNA template. This takes place in the cytoplasm on ribosomes. The ribosome reads the mRNA sequence in three-nucleotide units called codons. Each codon specifies a particular amino acid. Transfer RNA (tRNA) molecules bring the correct amino acids to the ribosome according to the mRNA codons, and these amino acids are linked together to form a polypeptide chain. This polypeptide chain then folds into a functional protein.

The regulation of geenitoiminta is crucial for cellular function and development. Cells control which genes are transcribed and translated, and at what levels, allowing them to respond to environmental cues and perform specialized roles. This regulation can occur at various points, including during transcription initiation, RNA processing, or protein degradation. Aberrant geenitoiminta is often implicated in diseases, including cancer.