DNA is transcribed to RNA, which is translated into protein by ribosomes.
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Gene expression converts the information in DNA into proteins through two linked steps. In transcription, RNA polymerase reads the template strand of a gene and synthesises a complementary messenger RNA, which in eukaryotes is capped, spliced and polyadenylated before use. In translation, ribosomes read the mRNA codon by codon, and tRNA molecules carrying matching amino acids are added one by one to build the polypeptide. Translation proceeds through initiation, elongation and termination, with a stop codon releasing the finished chain. This flow of information from DNA to RNA to protein is the central dogma of molecular biology.
Key ideas: Transcription: RNA polymerase reads the template strand 3 to 5 and builds mRNA 5 to 3; in eukaryotes mRNA is capped, spliced and polyadenylated. Translation at the ribosome: initiation at AUG, elongation as tRNAs match codons, termination at a stop codon. Each peptide bond costs about 4 high-energy phosphate bonds.
Common mistakes and connections: Mistake: the mRNA matches the coding strand sequence (with U for T), not the template strand, which is complementary to it. Another is thinking translation happens in the nucleus; in eukaryotes it is in cytoplasm. Links to genetic code and antibiotics that block ribosomes.
Typical speeds in bacteria. RNA polymerase adds about 50 nucleotides per second during transcription and the ribosome adds about 20 amino acids per second in translation. The interactive lesson shows this as a live animation or chart.
The insulin gene is transcribed into mRNA, which is translated into the insulin precursor protein.
DNA is transcribed to RNA, which is translated into protein by ribosomes.
Transcription and Translation is a advanced topic in Biochemistry, Environment & Industry. It builds on beginner and intermediate topics, so review those first if needed.
Study these earlier topics in Biochemistry, Environment & Industry first: RNA Types, Base Pairing, DNA Replication.
The next topics in Biochemistry, Environment & Industry are Genetic Code and PCR.
Yes. The interactive lesson includes a self-check question on Transcription and Translation, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.
Transcription and Translation is topic 27 of 127 in Biochemistry, Environment & Industry.
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