What are the steps involved in making a protein? Introduction
Before a protein can be built, the biochemical blueprints for its construction must be packaged and
transferred out of the DNA “library.” First, the specific sequence of DNA that codes for the protein
is transcribed into a complementary strand of mRNA. In eukaryotic cells, the mRNA then leaves the
nucleus and enters the cytoplasm. In all cells, the mRNA molecule attaches to a ribosome, where
tRNA anticodons translate the mRNA into amino acids. The completed amino acid chain, or
polypeptide, then folds into its final shape as a protein.
In this lab, you will model transcription of DNA and translation of mRNA while you decode secret
messages.
Skills Focus
Use Models, Sequence

Pre-Lab Questions
1. Sequence Describe briefly the process you will use to decode the messages.

2. Compare and Contrast What role do stop codons play in protein synthesis? What are they used
for in the coded messages?

3. Predict Which six letters will not appear in the coded messages? Give a reason for your answer.