Cracking the Codon Protein synthesis is the process our bodies go through to make proteins. During protein synthesis, our bodies make proteins from the code in our DNA. Protein synthesis contains two steps: transcription and translation. During transcription, DNA is converted into RNA. Our bodies need RNA to act as a code reader. Unlike DNA, RNA is single-stranded and contains the bases adenine (A), cytosine (C), guanine (G), and uracil (U). RNA’s bases code a bit differently than DNA. In RNA cytosine (C) still pairs with guanine (G), but adenine (A) now pairs with uracil (U). During the second step of protein synthesis, translation, the RNA translates a series of codons into amino acids. A codon is a group of three bases in a row in RNA. Each codon codes for a specific amino acid. Amino acids are the building blocks of proteins, and combine in long chains to make the proteins our body needs. In this activity, you will use the code found in DNA to uncover a secret message. You will go through the processes of replication, transcription, and translation to crack the code and uncover the mystery word. Directions: 1. During replication, DNA is copied. Use your knowledge of DNA replication to replicate the original DNA sequence in the table below. Write the replicated DNA sequence in the table. 2. Now that you have replicated the DNA sequence, the next step is to transcribe it into RNA. Remember, in RNA adenine (A) is transcribed into uracil (U), thymine (T) is transcribed into adenine (A), and cytosine (C) is transcribed into guanine (G). Write the transcribed RNA sequence in the table. 3. Next you will translate the RNA into amino acids. Remember, three RNA bases in a row is called a codon, and each codon codes for a specific amino acid. You will use the chart on the following page to determine which amino acid each codon codes for. For each codon, start in the middle of the chart and work your way outward. For example, the codon CAG codes for glutamine. 4. Each amino acid in the table is denoted by a letter, for example glutamine is letter Q. You will use these letters to crack the code and find the mystery word. Write the letters in the table to fill in the blanks. Replication Original DNA Sequence GGC GAG AAT GAA ACT ATT TGT AGC Replicated DNA Sequence Transcription Transcribed RNA Sequence Translation Mystery Message ____ ____ ____ ____ ____ ____ ____ ____