Year 12 / Genetics and heredity
From sequence to protein.
Transcription copies a gene into messenger RNA using complementary pairing, with U in RNA where DNA uses T. A ribosome then reads mRNA codons during translation. Transfer RNA brings the corresponding amino acids.
A change in DNA may alter an mRNA codon and hence a protein, but the genetic code is redundant: some substitutions leave the amino acid unchanged. Changes may also affect expression rather than coding sequence.
Transcription to RNA
Explore: Change one DNA base and compare the resulting mRNA triplet.
A DNA template triplet TAC is transcribed.
- Complementary RNA bases are A, U and G.
- AUG is a start codon and codes for methionine in the standard code.
Assumed knowledge
DNA base pairing.
Learning checkpoints & source
YOUR LEARNING CHECKPOINT- Distinguish transcription and translation.
- Use the codon concept to predict protein change.
READY TO TRY IT?