Transcription, Translation and the Genetic Code
This lesson connects molecular mechanisms, cell behavior and biological evidence. Instead of memorizing isolated terms, follow what changes, what is measured, where the process occurs and why the outcome matters to a living system.
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, and 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, which influences protein folding and function.
Core concepts
1. Transcription
RNA polymerase uses one DNA strand as a template to synthesize complementary RNA.
Observation or application: 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 or application: Alternative splicing can produce different mRNAs from one gene.