Name: _________________________________________ Date: __________________ Sec: _____
How Genes Work: Making a Protein
Introduction:
By the end of this activity, you will know how to read the genetic code to build proteins. You will
recognize that the sequences of bases in a DNA molecule direct the formation of proteins. Genes
usually code for a sequence of amino acids that make up a large part of a protein molecule.
Procedure:
1. Study the table below; it shows the codons for each amino acid (the Genetic Code).
2. Below the table is the sequence of RNA bases that makes beef insulin, a hormone that controls the
uptake of glucose from a cow’s blood.
3. Divide the RNA bases into groups of three.
3. Use the Genetic Code and the sequence of bases to write the three-letter abbreviations of the amino
acids in the beef insulin molecule.
4. Answer the questions below the representation of the beef insulin molecule.
1
5
10
15
20
UUUGUCAAUCAGCAUCUGUGUGGGAGUCACCUAGUCCAGGCCCUAUAUUUGGUUUGCGGC
21
25
30
35
40
GAGAGAGGGUUCUUUUACUACCCCAAAGCAGGUAUUGUGGAACAGUGUUGUCGUUCUGUU
41
45
50
UGUUCGUUGUACCAAUUGGAGAAUUAUUGUAACUAG
Beef Insulin Molecule
Fill in the circles of the beef insulin molecule below with the three-letter abbreviation for each amino
acid.
1. Disulfide bonds in proteins form between a pair of amino acids of a certain kind. Using the
diagram you have just completed, look up the full name of those amino acids and write their
names below:
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2. Disulfide bonds are a major factor in determining the overall shape of a protein molecule. Why is
this important?
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