Proteins and Traits Review Sheet
LT15: Explain the function of proteins in living organisms, and the connection between proteins and inherited traits.
Be sure that you can do the following:
1. Define traits.
2. Give examples of structural and functional proteins, and explain why proteins are important to living things.
3. Describe the structure of a protein molecule, including how a chain of amino acids can fold to make a threedimensional protein.
4. Explain the difference between a “functional” and “non-functional” protein.
5. Define enzymes, and describe how functional enzymes perform their functions.
6. Explain what the “lock and key” model of enzymes is, and why this model can explain why enzymes are
specific to substrates, or do not work under certain environmental conditions.
7. Describe how the type of protein produced in the body can result in the type of trait we see expressed in
individuals. Use the proteins we have talked about in class so far (MC1R, lactase, sickle cell) as examples.
Practice Questions
1. List at least 3 of each type in the chart below.
Structural Proteins
Functional Proteins
2. There are only about 20 different amino acids that make up proteins, and yet there are thousands of
different kinds of proteins in the body. How can such a small number of amino acids make so many
different proteins?
3. Draw diagrams showing what a functional lactase enzyme will do with lactose, and what a denatured
lactase enzyme will do with lactose. Label the molecules and describe what is happening.
Functional lactase + lactose
Denatured lactase + lactose
4. Fill in the charts for the three proteins listed.
Protein
What does the protein do?
What trait do we see as a result?
MC1R
Protein
What does the protein do?
What trait do we see as a result?
Lactase
Protein
Hemoglobin
What does the protein do?
What trait do we see as a result?