Transcription, Translation and the Genetic Code
You can now identify the main components, explain the mechanism step by step, interpret an observation and distinguish related ideas.
Big idea
RNA polymerase uses one DNA strand as a template to synthesize complementary RNA. In eukaryotes, introns are removed and exons joined; a cap and poly-A tail support mature mRNA.
Learning goals
- Transcription: RNA polymerase uses one DNA strand as a template to synthesize complementary RNA.
- RNA processing: In eukaryotes, introns are removed and exons joined; a cap and poly-A tail support mature mRNA.
- Genetic code: Three-base codons specify amino acids or start and stop signals; the code is redundant but unambiguous.
- Translation: A ribosome reads mRNA codons while tRNAs deliver amino acids using complementary anticodons.
- Sequence to structure: The nucleotide sequence determines amino-acid order, influencing protein folding and function.
Core concepts
1. Transcription
RNA polymerase uses one DNA strand as a template to synthesize complementary RNA.
Observation: A gene's base sequence is copied into a primary RNA transcript.
2. RNA processing
In eukaryotes, introns are removed and exons joined; a cap and poly-A tail support mature mRNA.
Observation: Alternative splicing can produce different mRNAs from one gene.
3. Genetic code
Three-base codons specify amino acids or start and stop signals; the code is redundant but unambiguous.
Observation: Several codons may specify one amino acid, but each codon has one meaning.