AP Bio Lab 3--Practicing with 3-D Protein Structure Directions: In this ...

Name__________________________________________
Date______________________
AP Bio Lab 3--Practicing with 3-D Protein Structure
Directions: In this lab we will use strips of paper to simulate polypeptides. We will manipulate the paper to demonstrate
the four levels of protein structure.
1. Primary Structure:
What determines the primary structure of a protein?__________________________________________________
What are the monomers in a polypeptide called?____________________________________________________
What two functional groups are present in all monomers?_____________________________________________
How many common monomers exist?____________________________________________________________
Draw the basic structural formula for an amino acid in the box. Label the parts of the molecule in the diagram.
The “R” groups can have several
properties, list them below:
_______________________________
_______________________________
_______________________________
What is the name of the bond formed between 2 amino acids? Draw this bond below.
What molecule is released by the
What is the name of the molecule
formation of the bond shown here? formed by one of these bonds?
_______________ __________________________

Name__________________________________________
Date______________________
2. Secondary Structure:
Follow the directions below to assemble your chain of amino acids into a secondary structure. Cut out the two
rectangles on the next page cutting along the solid black lines. Fold one rectangle, from the short side into a pleat. After
folding, cut carefully along the dotted black line. Cut the other rectangle carefully at the dotted lines. Using your pen or
pencil, carefully wrap the paper around your pen/pencil to form a coil. Try not to rip the paper.
What is the name of the secondary structure that looks like a coil?_______________________________
What is the name of the other secondary structure?___________________________________________
Both of these structures are formed by the hydrogen bonds that form between adjacent chains. In the box below
draw this interaction (The double bonded O in the peptide bond interacts with the H on the amino group of an adjacent
peptide bond)

Name__________________________________________
Date______________________
Part 3: Tertiary structure: After building the secondary structures, wrap your polypeptide into a glob. This represents
tertiary structure.
What is the primary cause of tertiary structure?______________________________________________________
Two side chains containing a sulfhydryl group can interact to make strong, covalent_________________________
A side chain containing a positively charged atom will form and _______________________ bond with a side chain
containing a ________________________ charged atom.
Hydrogen atoms involved in polar bonds will form _____________________ bonds with oxygen or nitrogen atoms.
Part 4: Quaternary structure.
Place the two chains of polypeptides together into a complex. This represents the final shape of a protein.
What interactions will contribute to the quaternary structure?___________________________________________
The final shape of a protein determines its ___________________________. A single amino acid that is
incorrectly used in the making of a protein can result in death.
Proteins main roles in living things are: _________________________, __________________________
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