1. Tertiary and Quaternary Protein Structure

2. Primary and Secondary Structure
Primary protein structure- Described by the sequence of amino acids joined by peptide bonds.
Secondary protein structure- Common structural motifs.
eg. Alpha helices, Beta sheets

3. So What’s Tertiary Structure
Tertiary structure is the overall shape of a single peptide strand.

4. Example Tertiary Structure

5. Same Protein, Different View

6. Same Protein, Yet Another View

7. One Final Look

8. What Determines Tertiary Structure?
Usually interactions between atoms in the R groups of the peptide chain.
Typically there is not a repeating pattern of bonding that determines the structure.

9. Common Interactions Determining Tertiary Structure.
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10. Quaternary Structure
The overall structure of a protein made up of more than one peptide chain.
Same interactions forming tertiary structure are responsible for forming the quaternary structure of a protein.

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12. Factors Affecting Structure
Temperature- High temperature overcomes hydrogen bonds
pH- protonation and deprotonation of acidic and basic residues
Salinity- affects hydration of the protein and bonding.

13. So what do proteins do? Your turn
Myoglobin
Collagen
Potassium channel
Monoamine oxidase
Insulin
Immunoglobulin

14. In your lab groups Roles Protein Structure (1 person)
Protein Function (1 person)
Relationship of Structure to Function (1 person)
Presenter (1 person)

15. Image References Protein Data Bank Proteins: 2a5t & 2a5s
PowerPoint Lectures Exclusively for Adpoters of Campbell and Reece Biology, 6th Edition. 2002, Benjamin Cummings