| Feature | Transcription | Translation |
|---|---|---|
| Location | Nucleus (in eukaryotes) | Cytoplasm (at ribosomes) |
| Template | DNA strand | mRNA strand |
| Product | mRNA molecule | Polypeptide (protein) |
| Key Enzyme/Organelle | RNA Polymerase | Ribosome |
Codon vs. Anticodon: A codon is a three-base sequence on the mRNA, while an anticodon is the complementary three-base sequence found on a tRNA molecule.
Sense vs. Anti-sense: In the context of the original DNA, the transcribed strand is the anti-sense (template) strand, while the mRNA produced matches the sense strand (except U replaces T).
Location Check: Always remember that while transcription happens in the nucleus, translation occurs in the cytoplasm or on the Rough Endoplasmic Reticulum.
Base Pairing Rules: When converting DNA to mRNA and then to tRNA, remember that RNA uses Uracil (U) instead of Thymine (T). A pairs with U, and C pairs with G.
Start and Stop: Memorize that AUG is the universal start codon. Stop codons do not add an amino acid; they simply terminate the sequence.
Directionality: Ensure you can identify the 5' and 3' ends; ribosomes move toward the 3' end of the mRNA.
One Codon, One Amino Acid: Students often forget that while one codon only codes for one amino acid, one amino acid can be coded for by multiple different codons (degeneracy).
tRNA vs mRNA: A common mistake is using the tRNA anticodon sequence to look up amino acids in a genetic code table; you must ALWAYS use the mRNA codon sequence.
Peptide Bonds: Many learners overlook that the formation of the peptide bond is a condensation reaction occurring between the carboxyl group of one amino acid and the amino group of the next.
